1. Speifications: Foot ring - 16"(40cm) in diameter . Centre hub hole - 2.1" (5.3cm) in diameter. Overall Dimensions: 16"L x 16"W x 2"H.Warm Tip:Please better measure the gas lift cylinder diameter before you purchase Metal Chrome Foot Rest,make sure it is the correct size to fit your chair or stool.       2. Stainless steel foot ring resists scratches.Plastic ring inside the metal centre hole of the footrest to avoid scratches on your gas lift cylinder. Black painted metal center spokes provide more stability & sturdibility of the structure.       3. Universal size:Fits standard 2" diameter gas lift cylinders.A good helper to relax your feet when stting on the stool chair with security.       4. Adjustable: Foot rest can be adjusted to comfortable height on gas lift cylinder.Once height is adjusted,lock the footrest with screw so it does not fail.