Fits 104/64 BCD 2X crankset and converts into single ring Narrow-wide tooth profile keeps the chain snug, allowing you to leave the chain guide behind Not for Shimano 12spd Hyperglide+ chain Not for SRAM T-Type/Flat Top chain Designed in UK, manufactured in Poland SPECS table{border-collapse:collapse;width:100%;} td{text-align:left;padding:8px;font-weight:350;} tr:nth-child(even){background-color:#f2f2f2} th{background-color:#eb212e;color:white;text-align:left;padding:8px;} .desc .specs-heading{font-size:24px;font-weight:600;padding-top:35px;border-top:3px solid #f0f0f0;display:inline-block;border-bottom:4px solid #eb212e;width:142px;margin:0;} Model 104 Round Ring Type Single (Anti-Chain Drop) Mount 4x104mm Teeth 38 Oval/Round Round Color Black Bcd 104 Size 38T