The ENVE Presta Valve Air Chuck features a simple and adjustable locking mechanism that secures the pump head to the valve stem while depressing and opening the valve simultaneously This process prevents air from leaking and ensures accurate pressure readings Constructed from stainless steel and aluminum, the ENVE Pump Head is ready for a lifetime of inflation duties The ENVE Presta Valve Air Chuck is manufactured by KCNC and fits rubber hoses standard on most floor pumps It uses a standard compression fitting with a locking nut, which requires a 12 mm wrench In cycling, tire pressure and inflation are a primary gateway to performance. Given that nearly every ride begins with a routine tire pressure check and top-off, we grew tired of difficult to handle, cheap, plastic, leaking, and otherwise annoying pumps and pump heads. Throughout the development of the ENVE Air Pressure Station, we collectively agreed that the best pump head for accurate inflation was a functional and reliable side-locking design, that’s been proven in the cycling world for decades. The ENVE Presta Valve Air Chuck promises to improve the performance of any pump.