Precision machined AL6061 cups for a superior fit and noise-free operation Low-friction dual seals protect the bearings from harmful contaminants Sealed dual-row premium flanged bearings Designed for installing Sram DUB 28.99mm spindle cranks into BB86/92 frames 86-92mm x 41mm BB86/BB92 SRAM DUB 28.99mm AL6061 90g Black