RING RTC4000 TYRE INFLATOR This is an impressively comprehensive compressor for such a small package. The inflator is primarily powered by abattery recharged via USB, but it can also be powered from acar’s 12V socket,and both cables come housed in the compactcasing. Integral to the unit itself are the 60cm air hose, along with attachments for inflating bicycle tyres and sports equipment.I had urgent reason to test the RTC4000,needing toinflate a spare tyre from 15psi to 60psi. The compressor was intuitive to use and did the job in afew minutes, although Idid have to restartit twice –perhaps it was saving itself from overheating on what was, to be fair, quite a big job.For occasional use,topping up pressures, and for ease of stowage in the car, it’s a perfect solution for £59.99. CC shop.ringautomotive.com