The Box one front load stem is a 318 A oversize stem designed specifically for BMX racing When used with our Triple Taper Alloy or Box One Chromoly (aka Maximus) handlebars you get the absolute stiffest cockpit available Features Cold-Forged & CNC Machined from 6061-T6 Aluminum Alloy Front-Load Clamp Design Fits 1 18" Steerer Tubes & A¸318 Handlebars