The absoluteBLACK's HOLLOWcage for Shimano Dura-Ace 9250 12-speed derailleurs makes the 9250 drivetrain whisper quiet. It features a carbon-polymer mono-plate construction with bespoke, oversized, full ceramic bearings and one of the most advanced silencing pulleys ever made.
- Designed for use with Shimano Dura-Ace 9250 drivetrains
 - Fits up to a 34t cassette
 - HOLLOWcage uses full ceramic bearings (Silicon Nitride ceramic balls and Zirconia Oxide ceramic races) that make the guide pulleys incredibly stiff for greater shifting precision
 - Incredibly silent (over 5-7dB noise reduction vs stock)
 - One of the lightest oversized cages on the market (71g)
 - The Silent Xring Pulley dampens the chain impact on the guide pulley teeth, eliminating the engagement noise