Torx T-30 bolt for greater reliability with standard slotted nut CNC machined 7075 with type II anodizing Long fits 110/4 &110/5 BCD for outer+inner ROAD oval chainrings, 104BCD oval 26/28/32T, 64BCD round 26/28/30T, 94BCD oval 30/32/34T Short fits 104BCD oval 34/36T, 110/4 and 110/5 CX oval 38T, and 104BCD round 32/34/36/38T For XT M8000 and XTR M9000 use original Shimano bolts For Road inner oval chainring only with original round outer, use original bolts TECH 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 T-30 Chainring Bolt Set Kit Single Size Short Material Aluminum Color Black Length Short (6.5) Quantity Set Of 4