Spring for gearbox index plunger (detent) for Norton upright and lay down gearbox, 1933-1957 also Cam plate plunger spring for upright gearbox, 1933-1948. Length: 1.2" (30.5MM); Diameter: 0.272 (6.9MM); ID: 0.194" (4.9MM)Original part numbers:3601, A2/352 - indexing plunger spring; cam plate plunger spring