The BSD TBT Sprocket is a real throwback to the glory days, inspired by classic designs but built for modern riding. Super tough 7075-T6 aluminium construction that's fully CNC machined with a dual thickness that's 8mm at the edges and tapers down to 6mm at the center to save weight. The 24mm center hole can run on any cranks thanks to the 19mm and 22m top hat washers that are included with the TBT Sprocket. ###section### Product Specs TYPE: Bolt On MATERIAL: Alloy WEIGHT: 70g (2.52oz) Colour: Polished, Black; Size: 25t, 28t