CeramicSpeed Preload RingsThe CeramicSpeed preload ring ensures correct preload adjustment for all SRAM DUB crank and bottom bracket combinations. Metal threads to ensure correct preload adjustment Internal o ring to provide secure fitment on crank spindle without needing glue Sleek design reduces areas for dirt to collect Compatible with all DUB Crank + bottom bracket combinations Comes with 1mm + 3mm spacers that match the outer diameter for a clean and tidy look regardless