Why you need an O2 Mobile Booster. We understand that it is very frustrating to have poor mobile signal in our homes, offices or businesses. Especially in today’s technology-filled world when we communicate, complete transactions and even make payments on our mobile phones, tablets and computers. O2 booster for Voice and Data, o2 3g signal booster & o2 4g signal booster boost your mobile signal Voice and Data, 5 bar signal guarantee at Any Places in UK.