Feeling sluggish? Can't get across town as easily as you could last week? It's not you, it's the bike. Or rather the tires. Time to give them some air. So you use your little frame pump (like the Crank Brothers Gem above) or you go to the nearest gas station or bike shop and use their free air but you never really know how much your putting in because there isn't a gauge on either. Well then, what you need is a tire gauge like the Sunlite Duo Sport pictured. It's easy to read, goes up to 160PSI (you'll never need that much), and works with both Schrader and Presta valves. Better yet is to have a floor pump at home like the Park Tool PFP 8 with gauge. It also works with both kinds of valves. Filling your tires before you go out will ensure a zippy commute. All three items in stock.