Conrod bolt and nut, part of bottom end overhaul kit, for Norton early small journal (1-1/2") twin cylinder engines, 250cc to 600cc., Made in UK, 5/16 inch BSC; also fits some BSAs.Set of one nut and one bolt. Original Part Number: D12/989; 17827 - big end nut x 1 D12/989; T2150 - big end bolt x 1