AP Racing have changed the cap headed bolts historically used for mounting discs to bells to an E8 6 Lobe bolt with an improved low friction coating.The 6 lobe bolt offers the following advantages over a cap head; More consistent clamping loads, lighter, better corrosion resistance, less prone to damage and improved airflow.Supplied as a kit of 12 bolts, nuts and washers and available in three different lengths to suit various applications.Bolts - CP3845-100 0.25" UNF x 0.875" - (22.22mm long / plain section 9.5mm / full thread 12.7mm)Bolts - CP3845-101 0.25" UNF x 1.00" - (25.4mm long / plain section 12.7mm / full thread 12.7mm)Bolts - CP3845-102 0.25" UNF x 1.062" - (27mm long, plain section 14.3mm, full thread 12.7mm)Nuts - CP2494-117 0.25" UNF Nut 7.3mm heightWasher - CP2494-1305 0.25" Stainless Steel Washer, 0.9mm thick