The eeWings and the included CNC aluminum bottom bracket preloader are the ultimate in stiffness and durability while only weighing a mere 400 grams The same weight range as premium carbon cranks but 20% to 30% stiffer Butted 3/2.5 titanium arms with CNC 6/4 titanium spindle, crank bolt, and hirth joint Bottom Bracket Compatibility: 30mm spindle only. BSA73mm, PF92, PF89.5, BB30 (External Bearing Only), PF30 (External Bearing Only), 392EVO Compatible with SRAM 3-Bolt Direct Mount Chainring Interface Brushed Titanium finish with laser etched graphics 10 year limited warranty through Cane Creek 170mm 30mm Titanium Direct Mount 400gUPC/EAN/GTIN: 840226148236