Campagnolo uses a hollow axle and light alloy cups/spacer with three cartridge bearings supporting the spindle. This bottom bracket is lighter and stronger than the Veloce model. 111mm is for use with double and triple cranks with seat tubes smaller than 34.9mm. For 34.9/35.0mm seat tubes, use the 115.5 Centaur (#0207). Use the Park BBT-5 (#2489) for installation.