These bolts go through the brake shoes and attach the brake adjuster bar. Each kit contains one 31058 bolt, one 31705 slotted nut, one K.19803 split pin and two flat washers (which are actually not listed in the factory parts catalog). Two kits required per front wheel. For later XK-120 with dual master cylinder and self-adjusting brakes and all XK-140. Made in England.