This is a standard #530 pitch chain with O-ring sealing. Features: 1. Solid bushings and rollers are precision centerless ground and shot-peened, to minimize friction and maximize strength. 2. Sideplates made of high-strength, heat-treated alloy steel to prevent stretching. 3. Protruding bushings help extend O-ring life and inhibit kinking. 4. Sideplate holes reduce weight, lower friction, dissipate heat, extend O-ring life, and facilitate self-cleaning. 5. Pins are quad-staked to the sideplates for more reliability.