Pro-Lite Aerobuster Seat Clamp Taking a closer look at the clamp for the Aerobuster models, our design team decided that a bit of fine tuning was in order The aerodynamic profile is the same, but the secondary lower clamp provides an added level of security, especially when considering that a Triathlon bike actually does spend a fair bit of time hanging from its seat (The last thing you want to be worrying about is your bike slipping off the rack while you are in the middle of the swim part of a race) Buy Pro-Lite Components from Chain Reaction Cycles, the World's Largest Online Bike Store.