Features:Made of high-quality aluminium alloy, fadeless and not easy to oxidize.To raise the height of amplifier to help create a real stereo surrounding sound.Amplifier feet to help absorb shock, to protect your amplifier.Rubber ring is detachable, very convenient and easy to use.Durable for a long-time use.Specification:Type: Amplifier FeetMaterial: Aluminum AlloyDiameter: 20mmHeight: 8mmScrew hole diameter: 3.5mmSurface treatment: Anodizing sand blastingRubber ring: DetachableWeight: Approx. 22gPackage list:4 * Amplifier FeetNote:Please allow slight error due to manual measurement. Thanks for your kind understanding.Installation Method:The amplifier feet can be installed from the inside of the chassis, or it can be installed from the outside of the chassis with self-tapping screws (suitable for wooden materials, self-tapping screws need to be self-matching, which means it's NOT included), or for 3M double-sided adhesive (self-matching, also NOT included)