I've been cycling for many years and have tried various Inflator's. This one is the best I've found. Easy to use, and store in your bike bag. Never leaks. NOTE: Just be sure the valve is in the "closed position" before screwing on you C02.
Takes some getting use to (after wasting 2-3 co2 cartridges.) You have to find the "sweet spot" on the control valve(open-close valve) when screwing in the CO2 or else it will leak as you screw it in.