ITEM NAME:F180 R160 Cycling Conversion Front Fork Bracket Parts Bicycle Disc Brake Adapter Descriptions: Made of aluminium alloy, durable and practical. Easy for installation and use. For 74mm caliper with 180mm/160mm rack disc. Specification: Name: bicycle rack disc brake adapter(without screws) Material: aluminium alloy Types: B-pillar F180/R160 Color: black Center distance: 74mm/51mm Application: Use with 180mm disc in front wheel Use with 160mm disc in rear wheel Package Included: 1 x bicycle rack disc brake adapter Notes: Transition: 1cm=10mm=0.39inch 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..For 74mm caliper with 180mm/160mm rack disc. Use with 160mm disc in rear wheel. Use with 180mm disc in front wheel. 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.