The catch is that it is a calls-and-SMS-only unit, not a 4G / 5G data booster. The £75 price buys you Band 8 (900 MHz) voice amplification for O2 and Vodafone networks, covering about one room (100 m²). If you only need to stop dropped calls and send texts — and you are on O2, Vodafone, giffgaff, Sky Mobile, Tesco Mobile, Lebara or Lycamobile — it is the cheapest legal way to fix it. If you need faster mobile internet data, you need a C-series 4G booster instead.

No. The G100 boosts Band 8 (900 MHz) voice, which is used by O2 and Vodafone. EE and Three run their voice services on different frequencies that this unit cannot tune into. If you are on EE, Three, SMARTY, iD Mobile, Plusnet, BT Mobile or Vectone, the G100 will not help — you need a multi-band C-series booster instead. If you are on giffgaff, Sky Mobile, Tesco Mobile (all O2) or Lebara (Vodafone), you are in luck — it works perfectly.

No. The G100 is a dedicated voice and SMS booster. It amplifies Band 8 (900 MHz) 2G / 3G calls and texts only. It will not speed up your 4G broadband, streaming or mobile data. The reason it is so cheap is that it does one job — making phone calls reliable — and it does that job well. If your priority is home internet, streaming or working from home over 4G, choose a Band 20 C-series booster instead.

Roughly one large room, an open-plan studio flat, a one-bedroom flat or a home-office spare room. 100 m² is about 1,076 ft² — think a 10 m × 10 m space. It will not cover a two-storey house, a large detached home or multiple rooms on different floors. If you need whole-house coverage, step up to the C200 (200 m²) or C250 (250 m²) range. For a bedsit, basement room or single office, 100 m² is more than enough.

You need at least 1 bar (a usable sliver) of Band 8 signal at the point where the outdoor antenna sits — usually on the window or outside wall. The G100 amplifies that weak donor signal up to a full-strength signal inside. If your phone shows zero bars and runs emergency-only when you stand outside, no Ofcom-legal booster in this price range will create signal from nothing. We recommend checking your outdoor signal in phone field mode before ordering.

Yes — all three run on O2, which uses Band 8 (900 MHz) for voice. The G100 boosts the physical radio signal, not any specific SIM or contract. giffgaff, Sky Mobile, Tesco Mobile and Lycamobile all ride on O2; Lebara rides on Vodafone. Just insert your existing SIM as normal — no new contract, no femtocell, no broadband dongle needed. EE-based MVNOs (Plusnet, BT Mobile, Vectone) and Three-based MVNOs (SMARTY, iD) are not supported.

Three reasons. First, the G100 is voice-and-SMS-only — no 4G LTE data band to engineer. Second, it is single-band (Band 8 only) rather than multi-band. Third, it uses a 3 dBi basic omni antenna and a 55 dB / 15 dBm entry-level amplifier instead of the higher-gain radios and directional antennas in the C-series. If you only need reliable calls in one room on O2 / Vodafone, you do not pay for 4G data or house-sized coverage you will never use.

You can install it yourself in minutes. The G100 ships as a three-plug system: stick the outdoor antenna on the window / wall, run the 3 m coax through the window, plug the indoor unit into a 240V mains socket. No drill, no professional installer, no wiring into your consumer unit. Most customers are up and running within 15 minutes. Lifetime technical support is included if you get stuck.

Two common reasons. First, many UK homes are built with thick stone, cavity walls, foil-backed plasterboard or reinforced concrete (especially basements) that absorb the 900 MHz Band 8 voice signal. Second, Wi-Fi calling depends on your home broadband and router — if your broadband drops or is congested, calls drop too. The G100 boosts the cellular radio directly to your phone, so calls work even when your broadband is down. Real UK tests show dropped-call rates falling from 18% to under 2% after install.

Yes. The G100 comes with a 365-day money-back guarantee and free return shipping. If the 3 dBi outdoor antenna cannot pull in enough Band 8 donor signal at your flat, or the 100 m² coverage is too small for your room, send it back within a year for a full refund. Most UK flats in towns and cities get at least 1 bar of Band 8 outdoors, which is all the G100 needs. We also offer lifetime technical support to help you position the antenna for best results.