Designed exclusively for the Kolossos Oversized Derailleur Cage, these pulleys give you even more options to customize your ride and maximize everyday or race-day performance. Kolossos oversized pulley wheels are built to last: aluminum cogs, serviceable bearings to resist the most challenging cycling conditions. **Please Note - compatible ONLY with Kolossos Oversized Derailleur Cages and available with road seals.