CENTER HOLE IS ABOUT 9MM FOR AN 8MM BOLT. THESE ARE 1/8" STEEL FORMED, SO THE BLINKER WILL BE TOTALED BEFORE THESE WILL BEND AT ALL (: 311H ON A BIKE LEFT ON A BIKE RIGHT @ *BOLT_WASHER 6x12mm OEM_HONDA 93401-06012-00 7/21A (91T) 91T @ *6MM X 10MM OEM BOLT 6X10 (CT70K1_TO_1977_CHAIN_GUARD) (SOLD_EACH) (90cc_cam_sprocket) 92101-06010-0A 1/22A (B64S) B64S