Features: * brand new and high quality *Made of high quality material, and practical to use *If the bicycle is a center-lock hub, it must be equipped with a center-lock disc.However, there are too few types of center-lock discs available on the market.If this is available, you can install six-pin discs. The-choice is even broader. *Installation requirements: The center distance between the six-nail disc and the hole is 44mm *Purpose: Install on the center lock hub so that it can install six-nail discs Specifications: Brand name: BUCKLOS Color: Red, Blue, Black, Gold Material: Auminum alloy Dimensions: Spacer: 42*0.1mm, cover: 44.7*9.3mm weight: 31.8g Process: CNC Anodizing Usage: Road bike, Mountain bike Features: Light weight Installation requirements: The center distance between the six.