The plastic seems pretty lightweight and not very rigid. I don't think this mat is suitable for anything other than a hard surface floor. When used on carpeted surfaces this mat will show indentations from your chair legs/wheels.
The size is nice and I like how it stays in place but it's too soft when you sit in a chair and try to move. A firmer mat would have been more desirable. Wished I could exchange it for a firmer mat.