This is the classic and simple 90 degree presta adaptor made by Silca for inflating disc wheels. Simply plug and lock this adaptor into your pump, press it onto your disc wheel's valve, and begin pumping! This task often requires two people- one to hold the valve adaptor, the other person to pump (for one person operation see Silca's Hiro V2 Locking Adaptor). Made of lightweight aluminum, this is a must-have for anyone with a disc racing wheel.