ITEM NAME:1 Set 11T Rear Derailleur Jockey Wheel Ceramic Bearing Guide Roller (Red) A#S Product Description Description: 1 Set 11T Bicycle Rear Derailleur Jockey Wheel Ceramic Bearing Aluminum Alloy MTB Mountain Bike Guide Roller Features: - Waterproof and drop-proof sax reed box can hold up to 8 sax reeds. - Suitable for saxophone reed storage, prevent loss when going out - Storage box is made of ABS, durable, moisturizing. - Convenient to carry. - Can be used as advertising gifts, redemption gifts, business gifts, award gifts, conference gifts, welfare gifts, personal gifts. Specifications: Main material: Lightweight aluminum alloy + non-resistance ceramic ball bearing Color: Red Size: 43.6x43.6x8.5mm Product net weight: 7.7g Specification: 11T Middle hole diameter: 6mm/0.24" Reducer sleeve inner diameter: 5mm/0.19'', 4mm/0.15'' Application: Compatible with most rear derailleur on the market Notes: 1. Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! 2. Please allow 1-3cm measuring deviation due to manual measurement. Included: 1 Set X 11T Bicycle Rear Derailleur Guide Roller.Included:1 Set X 11T Bicycle Rear Derailleur Guide Roller. Specification: 11T. Application: Compatible with most rear derailleur on the market. Main material: Lightweight aluminum alloy + non-resistance ceramic ball bearing.