Seat knob suit Norton Commando, aluminium, standard. with hole for retaining pin. Thread 3/8" UNF [SAE] 24tpi; OD 1.98" 50.2mm; OL 0.925" 23.5mm. No roll pin - see R-060695 Original part number: 060647; 064009 - knurled nut (dual seat)
