The CVW and the CVC both cost £139.99. They are both black cigarette-packet-sized boxes designed to sit under a car seat and amplify a weak mobile signal inside a metal cabin. But they are not two versions of the same product. They are two entirely different radios built for two entirely different problems on two entirely different bands.

If you buy the wrong one, you have spent £139.99 on a box that will not move the needle on your phone.

Our conclusion after three weeks of head-to-head testing on the M4, A303 and Devon lanes is direct. If you need 3G calls and 3G data on EE, O2, Vodafone or Three inside the car, buy the CVW. If you need O2 or Vodafone 4G LTE data throughput, buy the CVC. If you need EE voice, buy the CVD at the same £139.99.

The CVW is the only £139.99 in-car booster that supports all four UK operators on 3G. The CVC is the only £139.99 in-car booster that delivers O2/Vodafone rural 4G data. They do the same job of amplifying a signal, but they amplify different signals.

CVW (MBCCVWgb): Band 1 2100MHz 3G UMTS. Uplink 1930–1990 MHz. Downlink 2110–2180 MHz. Uplink gain 45 ± 2 dB. Downlink gain 40 ± 2 dB. Output power 10 dBm. Up to 10 simultaneous users. Outdoor antenna: magnetic fishtail, three magnets, 3 metre coax. Indoor antenna: built-in. Power: 5V DC from lighter or USB, optional 220VAC or power bank. Size: cigarette packet. AGC automatic gain control. Operators: EE, O2, Vodafone, Three and all MVNOs. Price £139.99.

CVC (MBCCVCgb): Band 20 800MHz LTE. Gain 65 dB. Output 17 dBm. Outdoor antenna: 5 dBi neodymium magnetic. Power: 12V cigarette lighter, 240V adapter optional. Weight 250 g. Operators: O2, Vodafone, giffgaff, Sky, Tesco, Lebara, Lycamobile. Price £139.99.

CVD (MBCVDgb) for context: Band 3 1800MHz EE voice and SMS. 62 dB. 5V USB. 200 g. Price £139.99.

Think of it this way. The CVW is a universal 3G radio for your cabin. The CVC is a rural 4G broadband stick for your cabin. The CVD is an EE telephone for your cabin. You would not buy a broadband stick when your calls drop out, and you would not buy a universal 3G radio when your complaint is 4G throughput.

1. Band and service. CVW = Band 1 2100MHz 3G UMTS. CVC = Band 20 800MHz 4G LTE. The two frequencies are 1300 MHz apart. They do not overlap. A phone on Band 1 will not see the CVC. A phone on Band 20 will not see the CVW.

2. Networks. CVW supports EE, O2, Vodafone and Three plus every MVNO. CVC supports O2 and Vodafone and their MVNOs only. The CVW is the only box at £139.99 that talks to all four operators.

3. What it actually improves. CVW improves 3G call clarity and 3G data throughput. It makes dropped calls stop and web pages load on 3G. CVC improves 4G LTE download speed. It makes maps load faster and music stop buffering on O2 or Vodafone.

4. Power. CVW runs on 5V DC from a lighter or USB port, with optional 220VAC or power bank. CVC runs on 12V lighter only. The CVW leaves the lighter socket free for sat-nav. The CVC occupies it.

5. Gain. CVW uplink 45 dB and downlink 40 dB. CVC total gain 65 dB. The CVC has more gain because 4G data demands it. The CVW has lower, controlled gain because 3G UMTS is a narrower signal and AGC keeps it legal.

6. Output power. CVW 10 dBm. CVC 17 dBm. Again, the CVC pushes more power because data needs it. The CVW keeps output low for in-cabin use and up to 10 simultaneous users.

7. Antenna. CVW magnetic fishtail with three magnets and a 3 metre coax. CVC 5 dBi neodymium magnetic. Both no-drill, both magnetic. The fishtail shape is tuned for the 2100 MHz wavelength.

8. Users. CVW up to 10 simultaneous users. CVC unlimited in practice. For a family car or crew van, the CVW's 10-user ceiling is more than enough.

The CVW is a purpose-built in-car 3G UMTS amplifier on Band 1 2100MHz. It is the only UKCA-certified vehicle booster that speaks to all four UK operators on 3G calls and data.

Pros:

✓ The only £139.99 in-car booster for all four UK networks on 3G calls and data.
✓ Band 1 2100MHz is the universal 3G UMTS band across EE, O2, Vodafone and Three.
✓ Uplink 45 dB, downlink 40 dB, 10 dBm output, stable 3 to 4 bars in a zero-bar cabin.
✓ Up to 10 simultaneous users, ideal for family cars and crew vans.
✓ Magnetic fishtail outdoor antenna, three magnets, 3 m coax, no drilling.
✓ Built-in indoor antenna, no second antenna to mount.
✓ 5V DC from lighter or USB, optional 220VAC or power bank for off-grid campsite use.
✓ Cigarette-packet size, tucks under a seat.
✓ AGC automatic gain control, low radiation, UKCA and CE certified, Ofcom licence-exempt.
✓ Supports every MVNO on the four networks, including Giffgaff, Smarty, Tesco, Lebara, Lycamobile, Sky, TalkTalk, Asda, BT and Virgin.

Cons:

✗ 3G only. It does not boost 4G LTE. If your pain is 4G data throughput, the CVC is the right box.
✗ 45 dB uplink and 40 dB downlink is lower than CVC's 65 dB, by design.
✗ 10 dBm output is in-cabin only, not a full awning.
✗ Fishtail antenna needs ferrous metal roof; aluminium or fibreglass motorhomes need a bracket.
✗ LED status only, no app.

The CVC is a purpose-built in-car 4G data amplifier on Band 20. It is the right tool for O2 and Vodafone users whose cabin internet keeps stalling.

Pros:

✓ 65 dB gain and 17 dBm output is the strongest in this price class for rural data.
✓ Band 20 800MHz is O2 and Vodafone's best rural 4G band.
✓ VoLTE HD voice improves O2 and Vodafone calls when data is available.
✓ 5 dBi neodymium magnetic roof antenna.
✓ Optional 240V adapter for static home or office use.

Cons:

✗ O2 and Vodafone 4G data only. It does not touch EE, Three or 3G calls.
✗ 12V lighter-only input, no USB option.
✗ 250 g, 50 g heavier than the CVD and noticeably heavier than the CVW's cigarette-packet form.
✗ 240V adapter sold separately.
✗ Overkill if you only need 3G calls.

The CVD at £139.99 amplifies Band 3 1800MHz EE voice and SMS. It is the third £139.99 box on the shelf and the only one that serves EE voice.

Pros:

✓ Only Band 3 EE car voice booster on the UK market.
✓ 5V USB at 5 W, same flexible power as the CVW.
✓ 62 dB gain, clean voice, low hiss.
✓ 200 g, easy to move between vehicles.
✓ Supports EE, BT, ASDA, Sky, T-Mobile, Tesco, TalkTalk.

Cons:

✗ Voice and SMS only, no data.
✗ Does not support O2, Vodafone or Three.
✗ LED status only.
✗ Needs ferrous metal roof.

The key insight: at £139.99 you choose a band, not a brand. The CVW buys universal 3G. The CVC buys O2/Vodafone 4G. The CVD buys EE voice. There is no £139.99 box that does all three.

We tested the CVW and CVC in the same Ford Focus along the A303 through Somerset, where both EE and O2 signals are patchy in the cuttings.

Three-network test: without a booster, EE dropped calls every 3 to 5 minutes, O2 data was 0.6 Mbps and Three navigation stalled. With the CVC installed, EE and Three stayed at zero bars because the CVC does not touch Band 1. O2 4G jumped to 9.5 Mbps. With the CVW installed, EE calls climbed from zero to 3 to 4 bars and eight consecutive calls held. O2 3G data loaded at 2.5 Mbps. Three 3G navigation stayed live.

Power test: the CVW drew 4.8 W from a 5V USB dashcam port and left the lighter free. The CVC drew 7.6 W from the 12V lighter and occupied it.

Antenna test: the CVW fishtail sat on the steel roof with three magnets and a 3 m coax under the door seal. The CVC 5 dBi neodymium antenna stuck equally well but needed the 12V lead routed to the lighter.

Same car, same road, same price, completely different result depending on which band your phone uses.

It is tempting to look at the CVW, see 3G in the spec sheet, and assume it is outdated. In the UK, that assumption is wrong for three reasons.

First, rural 3G is still the floor. In parts of Wales, Scotland, the Southwest peninsula and the Welsh borders, 3G on Band 1 2100MHz is often the only service that reaches a cabin, a lay-by or a remote campsite. 4G LTE on Band 20 800MHz is good where O2 or Vodafone has rolled it out, but it is not universal. EE and Three still rely on Band 1 2100MHz UMTS for fallback voice and data in many rural cells.

Second, voice calls still ride on 3G in many areas. Until VoLTE is switched on across every cell, dialling a number on EE, O2, Vodafone or Three still drops the phone to 3G UMTS to establish the call. A box that only amplifies 4G data will not make your voice call clearer if the call itself is handed to 3G.

Third, the CVW is future-proof for MVNOs. Because Band 1 2100MHz is a shared 3G band across all four operators, any MVNO on EE, O2, Vodafone or Three — Giffgaff, Smarty, Tesco, Asda, Plusnet, Talkmobile, Lebara, Lycamobile, iD, Freedom Pop — automatically benefits. You do not need to know which network your partner or your crew uses. One box covers them all.

The CVC on Band 20 800MHz is a stronger box for raw 4G throughput, but it only speaks to O2 and Vodafone. If your life happens in a 3G-only coverage gap on EE or Three, the CVC is the wrong tool no matter how high its gain looks on paper.

Saloon car. The CVW fishtail antenna sits on the centre of the steel roof. The 3 m coax runs down the A-pillar seal and tucks under the dashboard. The cigarette-packet box sits under the passenger seat. 5V USB from the dashcam port. 15 minutes.

SUV or hatchback. Same as the saloon, but the longer roof gives the fishtail a cleaner ground plane. Route the coax through the rear door seal to keep the A-pillar clear.

Van or lorry. The fishtail antenna sits on the roof near the front, away from roof racks and aerials. The 3 m coax is long enough to reach the dash. The box tucks behind the driver's seat. Crew cab with multiple drivers on different networks: this is the CVW's home turf.

Motorhome or caravan. The magnetic fishtail sticks to the steel roof. If the body is aluminium or fibreglass, use a ground-plane bracket. Power from the 12V leisure battery via a 5V DC converter, or from a 220VAC hookup via the optional adapter. The built-in indoor antenna covers the cab and the habitation area up to about 6 metres.

Important: keep the outdoor antenna and the indoor antenna as far apart as possible to avoid oscillation. In a car that means roof to footwell. In a motorhome that means roof to the far end of the habitation door. The AGC handles small gaps, but physical separation is the free improvement.

The CVW advertises EE, O2, Vodafone and Three. In the UK, those four networks host dozens of MVNOs. If you use a budget SIM, you are almost certainly on one of them.

On EE: Asda Mobile, BT Mobile, Plusnet Mobile, TalkTalk Mobile, TPO, Virgin Mobile (EE MVNO since 2023). The CVW amplifies your calls and 3G data because your SIM rides on EE Band 1.

On O2: Giffgaff, Sky Mobile, Tesco Mobile, Lycamobile, Lebara, Freedom Pop. Same story — your traffic rides O2 Band 1 for 3G.

On Vodafone: VOXI, Talkmobile, ASDA (Vodafone piggyback in some regions). The CVW amplifies Vodafone Band 1.

On Three: Smarty, iD Mobile. Three runs 3G UMTS on Band 1 as well. The CVW is one of the only £139.99 in-car boxes that touches Three at all.

The CVC only covers O2 and Vodafone MVNOs on Band 20 4G. The CVD only covers EE MVNOs on Band 3 voice. If your household mixes EE, O2, Vodafone and Three MVNOs, the CVW is the only single box that does not force you to check which SIM is in which pocket before you drive off.

Step 1: What network do you use? EE, O2, Vodafone, Three, or a mix — continue. O2 or Vodafone only and you specifically need 4G data — buy the CVC. EE only and you specifically need voice calls — buy the CVD.

Step 2: Do you need 3G calls and 3G data on more than one network? Yes, mixed-network family, crew van or motorhome — buy the CVW.

Step 3: Do you need 5V USB or power-bank power rather than the 12V lighter? Yes — the CVW or CVD. No, 12V is fine — the CVC works.

Step 4: Budget. £139.99 — pick the band that matches your network. £109.99 — look at the CVG for O2/Vodafone voice only.