Cane Creek Angleset Series Zero Stack Headset Allows you to transform the head angle of your bike (steeper or slacker) Available as a +/- 1.0 degree headset or as a kit that includes additional cups for +/- 0.5, 1.0 and 1.5 degree adjustability Rotate each cup 108 degrees to create a steeper or slacker angle Headset self aligns to properly load the bearings Designed to work with 1 1/8" straight steerer forks ZS49-ZS49/30 fits: 49mm ID headtubes (1.5 traditional) ZS44-ZS49/30 fits: Tapered headtubes- 44mm ID top (1 1/8" ZeroStack), 49mm ID bottom (1.5 traditional) ZS44-ZS56/30 fits: Tapered headtubes - 44mm (1-1/8" ZeroStack) ID top, 56mm ID bottom (1.5mm ZeroStack) ZS49-EC49/40 fits: 49mm (1.5" Traditional) ID head-tubes - 1.5" to 1-1/8" Tapered Steerer)