Aaron RossÌÎÌ__ÌÎÌ__ signature BOSS stem is a classic top load design with 52mm of reach and a 35mm rise Aaron RossÌÎÌ__ÌÎÌ__ signature BOSS stem is a classic top load design with 52mm of reach and a 35mm rise Headset pre-load bolt recess (32mm diameter) Six bolt clamping configuration 6061-T6 aluminum, CNC machined