Shimano bb91 mtb press fit bottom bracketcomplete press fit bottom bracket assembly for shimano hollowtech ii mtb cranks for use with specialized frames with a 84 5mm bottom bracket shell width features cups are made from fibre reinforced polymer material which reduces the risk of frame noise and damage set includes left and right hand cups frame shell width 84 5mmcup outer diameter 42mmcompatibility specialized frame specifica 2 year warranty is offered with all shimano products from chain