Titanium spindle Light weight 150 grams/pair (225g with cleats) Low friction needle and ball sealed cartridge bearings Free float for perfect bio-mechanics.11 mm stack height Step-down entry, bi directional release. Cleat binding ring forged from Cr-Mo, hardened and CNC machined for optimum strength and wear.Custom NBR rubber lip seals keep grease in and dirt out.Precision needle roller bearings partnered with sealed ball bearings give perfect low friction rotationand durability