Specification: 100mm x 45mm x 50mm or 4 inch x 1.8 inch x 2 inch; 5/16inch (M8) bolt size; Weight: 0.4kg. Max load: 50kg (110lbs); The recommended distance of each two isolators is 24 inch, e.g. 63~99 isolators are needed for a room aera of 215~322 sq ft. Easy To Install: The base has 1 bolt hole on base for rigid mounting when used for supporting machinery, easy installation on ceilings, floors, walls, ducts, etc. Wide Application: The can be used in bedroom, studios, home theaters, houses, hotels, , karaoke room etc. Can be mounted to ceilings, walls, pumps. Colour: Black + Red Material: Plastic + Metal Package Contents: 4 * Capacity Spring Vibration Isolators Only the above package content, other products are not included. Note: Light reflection 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.