Isolate It: Sorbothane Large Vibration Isolation Washer 5" OD x 3.1" ID x 1" Thick 30 Duro - 4 Pack Outside Diameter: 5" Inside Diameter: 3.1" Thickness: 1" Supports between 30lbs and 65lbs per ring Absorbs up to 94.7% of vibration Isolate Valuable Shipments and Loads During Transit Sorbothane Part Number: 0572160-30 Durometer: 30 (Shore OO)