If you're dealing with annoying vibrations from equipment or need to protect valuable items during shipping, these Sorbothane washers are game-changers! Each washer measures 5 inches in outside diameter with a 2.5 inch inside hole and 1 inch thickness. The 50 duro rating means they're firm enough for heavy-duty use but still provide amazing vibration absorption - we're talking about 94.7% vibration reduction! Each ring can support between 95-230 pounds, so a set of four can handle some serious weight. They're perfect for placing under washing machines, exercise equipment, audio gear, or even furniture to reduce noise and prevent walking. For shipping protection, put them between layers of plywood with your cargo - they'll soak up shocks and impacts during transit. The black urethane surface is durable and won't harden or crack over time. Made in the USA, these isolators feature non-skid properties too. Just be aware they contain plasticizer that might cause slight discoloration on some surfaces with prolonged contact. Installation is straightforward - just make sure both top and bottom surfaces are flat and supported. Your equipment (and your ears) will thank you!