Gravity lock with spring & big cup bottom Gravity Lock with spring with big cup bottom to be used directly on plastic tubes without top plates. Shaft / inner sealing for an optimal seal between the cap and the spindle bolt. (Suitable for plastic dye tube having sizes-63OD x 57ID / 62OD x 54 ID). Also available without lever arm for opening for automatic loading and unloading. Spring pressure at half spring travel. Spring: 2.65mm~180mm N Standard