AMGYM LB Bumper Plates have the consistent dead bounce, durability, and distinctive smooth finish athletes have come to expect from the HG line. Each bumper is an IWF standard 450MM in diameter, but with a thinner width than most comparable plates on the market, enabling more weight to be loaded on the bar. SPECIFICATION Plate Width Breakdown: 10LB- 1.0 inch 15LB- 1.3 inches 25LB- 1.8 inches 35LB- 2.4 inches 45LB- 2.9 inches 55LB- 3.3 inches Diameter: 450MM (+/- 3MM) / 17.72" (IWF Standard) Collar Opening: 50.40MM / 1.98" Stainless Steel Inserts Minimal Bounce