... , held in place between Shaft and Short Spring.6. Insulator Rings - Ceramic, three provided, 12.5 mm OD, 8.3 mm ID ... . Two rings measure 4 mm thick, the other measures 3 mm thick ... , held in place between Shaft and Short Spring.8. Insulator Rings - Ceramic, three provided, 15 mm OD, 10 mm ID. Two measure ...