Deflecto Premium Glass Chair mats. Premium Glass chair mat is a clear, elegant and functional alternative to traditional plastic desk chair mats. This tempered glass chair mat is ultra-versatile and can be used to protect carpet or hard floors, while complementing the design of any office. The Premium Glass chair mat is made of sand and recycled glass, not oil. The 1/4" thick tempered glass chair mat will support a combined user and chair weight of up to 1.000 pounds. The smooth, ergonomic, easyglide rolling surface resists indentations and makes chair movement nearly effortless. This can help reduce stress and strain on a user's back and legs. Scratch-resistant surface, beveled edges and radius corners offer a smooth, refined look.