HRP's New HD Clutch Cannons. We designed this cannon with dual Quad seals, (or X-rings as they are called) to ensure no leakage even under the most severe conditions. We have also designed this cannon accept different size bearings, the typical cannon bearing which has an OD of 2.850 or a larger bearing that has an OD of 3.050. All cannons are "Hard Coat Anodized" black for long life.