The FSA Orbit XL21 1/8" Headset is something of a classic in the FSA line-up the Orbit XL II has forged and machined alloy cups top and bottom giving low weight and a high degree of accuracy. A split crown race simplifies fitting and a pair of angular contact cartridge bearing promise long-lasting performance. FSA Orbit XL2 1 1/8" Headset Features 1.1/8” 36° x 36° ACB upper bearing; Oversized industrial lower bearing Forged chromoly lower cup 6061T6 upper cup Industrial cartridge sealed lower bearings Forged chromoly crown race Gyro compatible Stack height: 15.4 + 16 = 31.4mm