Fsa Orbit C-40 Acb, Headset, Is42/28.6 | Is52/40

* 1-1/8" 45/45 ACB upper - 42mm ID * 1.5" 36/45 ACB lower - 52mm ID * Compatible with carbon or alloy head tubes * For 1-1/8" to 1.5" tapered steerers * 16.3mm stack height * 74.2g