Drop-Stop B is compatible with 10/11/SRAM 12sp chain and Flat Top/Transmission chains. Not compatible with Shimano 12 speed Hyperglide Elliptical shaped for improved power transmission Standard 4-bolt ring with Drop-Stop tooth design to prevent unwanted chain drop Made in the USA from 7075-T6 aluminum alloy 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 Drop-Stop B Ring Type Single (Anti-Chain Drop) Mount 4x104mm Teeth 32 Oval/Round Oval Color Black