[Soundproofing and anti-scratch] the height of the fixed glide feet of office chairs is equal to the height of the mounting feet. It is suitable for preventing the air pressure rod from damaging the floor. [Suitable for all types of flooring] fixed stationary have good adhesion, maintain stability on floor surfaces (wood, tile, laminates), greater grip than casters, and reduce friction, vibration and noise. [Replacement caster] replacement slides are suitable for a variety of swivel chairs (exclusive armchairs, office chairs, game chairs, tables and chairs), very suitable for rolling up your stool or office chair into a more stable, fixed type. [Efficient Installation] The replacement office chair wheels are easy to assemble and disassemble, no screws are required, just grab the old casters and pull out. Then push the replacement chair wheels into the holes. Good grip on movements: These sliding devices maintain stability on floor surfaces (such as wood, tiles and laminates) while providing more grip than castors. Easy to install: It is very easy to install without any tools. Than wheels: avoiding the "chair rolling effect" when they get up from a table or desk, and is designed for people who have difficulty getting in and out of the ice floe. Protect your carpet: It won't chew on your carpet like some well-known wheels. -Ideal for unusual situations: ideal for moving surfaces such as boats and, and floors, that are not too flat. Durable and Super QuietFixed casters have good grip, maintain stability on the floor surface and more grip than casters. In addition, we also give 5 foot patches to help you reduce friction, vibration and noise. Color: BlackMaterial: NylonSize: Base Diameter 52mm, Plunger: 11x22mm, Installation Height 35mmPackage Contents:5*Swivel Chair Fixed Casters5*Foam InsertsOnly the above package content, other products are not included. Note: The light and different displays may cause the color of the item in the picture to be slightly different from the real thing. The allowed measurement error is +/- 1-3cm.