[Mute and prevent scratches] The height of the fixed feet of office chair glides is to the height of the mounting feet. It is suitable for preventing the air pressure rod from damaging the floor. [Suitable for all kinds of floors]Fixed stationary have good traction, maintain stability on floor surfaces (wood, tiles, laminates), greater traction than casters, and reduce friction, vibration and noise. [ caster replacement]Replacement glides are suitable for different swivel chairs (executive chairs, office chairs, game chairs, and chairs) suitable to roll the stool or office chair into a more stable fixed type. [Efficient installation]Replacement office chair wheels are easy to install and remove, no screws are required, just grab the casters and pull out. Then push chair wheels replacement into the holes. Good traction for movements: These sliding devices maintain stability on floor surfaces (such as wood, tiles, and laminates) while providing greater traction than casters. Easy to install: is easy to install without any tools. than casters: By avoiding the "rolling chair effect" when up from a table or desk, a is provided for people who have difficulty in and out of the chair. Protect your carpet: will not chew carpet like -known casters. -perfect for atypical situations: perfect for moving surfaces, such as boats and , and floors that are not too flat. Heavy-Duty and Super Quiet Fixed casters have good traction, maintain stability on a floor surface, and greater traction than casters. In addition, we also give 5 foot pads to help you reduce friction, vibration and noise. Colour: black Material: nylon Size: Base diameter 52mm, plunger: 11x22mm, installationheight 35mm Package Contents: 5 x Swivel chair fixed casters 5 x Foam pads Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.