The 40-Series sets the standard for performance, durability and value. Drawing from the Premium 110-Series Design, the 40-Series incorporates all the features necessary for a durable, light-weight, long-lasting headset. Technical Description EC34/28.6/H16/K|EC34/30 /H12/K Top Type EC - External Cup Top Head Tube Inside Dia. 33.95mm Stem Clamp Dia. 28.6mm Top Stack Height 16mm Top Bearing Type Black Oxide, Sealed Bottom Type EC - External Cup Bottom Head Tube Inside Dia. 33.95mm Crown Race Seat Dia. 30.015mm Crown Race Type Steel, Face-Sealed Bottom Stack Height 12mm Bottom Bearing Type Black Oxide, Sealed Material 6061 Weight 98g Part Number BAA0068K The 40-Series is the workhorse of Cane Creek's headset line-up. Representing the balance of performance, durability and value, the series incorporates all the features necessary for a durable, light-weight, long-lasting headset.