The incredibly flat bolt and washer (2.5mm thick) combination does not destroy you race suit, your rib protector, or your body. They enable you to tighten the seat bolts without fear of the washer pulling through, as they often do with plastic countersunk washers, or bottoming out as they can do will regular steel washers. The design of the washer is such that it allows the head of the bolt to twist in the washer which stops the seat from breaking during the twisting forces generated by the chassis. Sold individually with 1x Bolt and 1x Washer or as complete kit. KIT INCLUDES: 2 - 60mm Stainless low profile bolts 4 - 25mm Stainless low profile bolts 2 - 30mm Stainless low profile bolts 8 - M8 25mm Stainless ultra low profile washers 8 - M8 "FLANGED" Nylocks