The Cervélo Internal Cable Stop (ICS) is required to properly route a rear brake on the SLC-SL, Soloist Carbon, and Soloist team road bikes, as well as all models of Cervélo TT bikes. Not only does the ICS give you optimal braking power, but it ensures that your cable routing will be as aero as possible. Anodized black, one size fits all frame models -- and you only need one per bike.