Trekkie inspired 100% CNC machined 7075 aluminum chainringOffset 1/8` teeth provide improved chain alignment15/16` (24mm) bore with 19mm and 22mm adaptors12mm thickness withstands the abuse of BMX riding1pc/3pc28T7075ALBlack1/2` x 1/8`StandardUPC/EAN/GTIN: 888571102039