If you have metal sled base chairs that are ruining your floors then you should look at this Flexi-Felt model designed specifically to fit tubing of 7/8 inch (22mm).
Once the unit is installed properly it is very difficult, almost impossible, to remove . Our sled base models offer unsurpassed floor protection with the largest surface contact area on the market. Our patent pending antiroll system is guaranteed to keep the Flexi-Felt well aligned.
The product is guaranteed for 5 years