The CVGD amplifies two separate radio frequencies in one box: Band 8 at 900 MHz (880–915 MHz uplink / 925–960 MHz downlink), which carries 2G GSM voice calls and SMS across EE, O2 and Vodafone, and Band 3 at 1800 MHz (1710–1785 MHz uplink / 1805–1880 MHz downlink), which carries 4G LTE mobile data across EE, Vodafone and Three. A normal booster tunes to one band only; the CVGD's dual-band design means a single cigarette-box unit improves both your calls and your data instead of needing two separate amplifiers. It deliberately does not touch 5G, 3G, Band 20 (800 MHz) or Band 7 (2600 MHz).

This is the most important honest point. The CVGD boosts Band 3 (1800 MHz) 4G data. EE and Three run strong Band 3 4G, so their customers see the data lift. O2 and Vodafone customers, however, get most of their 4G on Band 20 (800 MHz) rather than Band 3 — and the CVGD does NOT boost Band 20. So an O2 or Vodafone driver should expect clearer 2G calls on Band 8, but their 4G data speed will only improve if their local cell happens to carry Band 3 1800 MHz. If your priority is O2/Vodafone rural 4G on Band 20, the CVC (Band 20 unit, GBP 139.99) is the right choice, not the CVGD.

Three operates no 2G network in the UK — all Three voice calls already run over 4G VoLTE. The CVGD boosts Band 8 (900 MHz) 2G voice, a band Three does not use, so the voice leg is not improved for Three customers. What Three customers do get is a stronger Band 3 (1800 MHz) 4G LTE data signal, which also makes their VoLTE data-backed calls more reliable because the underlying 4G connection is cleaner. If you are a Three driver whose main complaint is dropped calls, check whether the issue is weak 4G (the CVGD helps) rather than a 2G gap (which does not apply to Three).

The CVGD is the flagship of the Boost4U vehicle range. The premium buys you the only dual-band unit (Band 8 2G voice + Band 3 4G data in one box), the only in-car model covering all four UK host networks (EE, O2, Vodafone, Three), up to 15 simultaneous users, a neodymium magnetic roof aerial stable to 70 mph, and 5V vehicle power. The CVL at GBP 169.00 is a single-band Band 7 (2600 MHz) 4G unit for EE/Vodafone only, with unlimited users but no 2G voice band. Choose the CVGD if you need both calls and data across all networks; choose the CVL if you only need EE/Vodafone Band 7 4G data and want unlimited users.

You need at least 1 bar of outdoor 4G LTE signal at the point where the magnetic roof aerial sits. The CVGD amplifies that weak donor signal up to ≥45 dB uplink / ≥40 dB downlink into a strong cabin signal, typically lifting 4G speeds from 1–5 Mbps to 10–30 Mbps. If your phone shows zero bars and runs emergency-only outside, no Ofcom-legal booster in this price range can create signal from nothing. We recommend checking Band 3 4G signal in your phone's field-test / engineering mode at the roof position before you order — this is the single most important pre-purchase check.

The CVGD supports up to 15 simultaneous users and devices. That is far beyond a normal family car (four phones + a tablet + a sat-nav) and easily covers a small works van, a taxi or a motorhome. Each device still uses its own SIM and data plan — the CVGD is not a router and does not create Wi-Fi — but every handset and tablet in the boosted cabin area benefits from the cleaner Band 8 and Band 3 signal at the same time. If you need more than 15 concurrent users, the CVL offers unlimited users instead.

No, and that is a deliberate honest warning. The neodymium magnetic aerial relies on a steel roof to grip; on aluminium, carbon-fibre or fibreglass / GRP motorhome roofs the magnet will not hold at motorway speed. The box includes an adhesive mounting pad for non-steel roofs, which bonds the aerial base in place, and we also offer an optional permanent screw bracket for a rock-solid fit on a GRP coachbuilt motorhome. If you run a steel-framed van conversion or a metal-roofed car, the magnet alone is stable up to 70 mph / 113 km/h without any fixing.

No. The CVGD boosts Band 8 (900 MHz) 2G GSM voice/SMS and Band 3 (1800 MHz) 4G LTE data only. It does NOT boost 5G NR, it does NOT boost 3G UMTS, and it does NOT boost other 4G bands — specifically not Band 20 (800 MHz) rural 4G or Band 7 (2600 MHz) urban 4G. This is by design: it is a focused dual-band voice-plus-data amplifier. If your phone shows 5G and you want to improve 5G, no unit in this range does that; if your weak O2/Vodafone signal is on Band 20 rural 800 MHz, look at the CVC instead.

Yes, with the optional 240V AC mains adapter. The CVGD ships with the 5V car cigarette-lighter adapter; for a static caravan or campsite on hook-up you order the 240V AC adapter separately and power the booster from the EHU. The unit itself is identical whether run from the 5V car socket or the 240V adapter. This is useful for seasonal-pitch owners who want cabin / awning 2G calls and Band 3 4G data without the engine running. Note the coverage still tops out at 100 m², so it suits a caravan or annex rather than a whole house.

Yes, it is legal. The CVGD is Ofcom licence-exempt, UKCA and CE certified, and complies with UK mobile signal booster regulations. As long as you use it as supplied — ≥45 dB uplink / ≥40 dB downlink, dual Band 8 & 3 only, on a vehicle or caravan — you do not need to notify Ofcom or pay for a licence. Do not modify the unit, swap to a higher-gain external aerial, or fit it as a permanent fixed-home system; that would void the compliance and the warranty. And no, it is not a Wi-Fi Calling replacement: it strengthens the cellular radio path, it does not route calls over the internet, and it cannot help where the outdoor donor signal is genuinely absent.