Designed to protect wooden, tiled, slate and other hard floor surfaces from the scraping of wooden chair legs. Diameter of plastic glide mount is 20mm and so will suit wooden chair legs of greater than 25mm diameter or 25mm x 25mm square. These glides are virtually unseen and unsighted below eye level when in use. Most timbers used in chair legs are hard grain timbers and it is advisable to drill a slightly undersized (or no larger than the actual shank diameter) pilot hole in the centre of each chair leg during fitting to avoid splitting of the timber. The pilot hole can be 10-12mm deep so that the tip of the nail digs into the timber to retain the glide in place without it falling out when being moved. The slightly undersized pilot hole will also hold the glide in place when the nail digs into it. Simply hammer the Nail-on glides into the pilot hole. Note that all the weight loading of a chair is downwards and if fitted correctly the glides will not move. The result will be chairs that glide effortlessly on the strong felt coir rings. Maintenance of these glides is hardly necessary but occasionally fluff may need to be removed to keep them tidy and ensure no hard objects get trapped in the felt coir.