Bestbuy offers Staples 36"x49" Flat-Pile Carpet Chair Mat for $22 (reg $80.49) with free shipping.

Product Description:
Extend the life of your flat pile commercial carpet (up to 1/8" thick including padding depth) by protecting against chair caster wear and tear. The perfect addition to your workspace, this chair mat provides a smooth surface that enhances ergonomic comfort by allowing your rolling office chair to move freely. Easy to handle, this chair mat features rounded AnchorBar cleats (studs) that hold your mat in place and are gentle on carpets and fingers (no sharp spikes). This chair mat is made with durable vinyl that is GREENGUARD Gold Certified for low chemical emissions to promote a healthier workspace. Designed for use on carpeted surfaces only, do not use on hard floors.

• Essential floor protection: Protects flat pile commercial carpet up to 1/8" thick (including padding depth) from chair caster wear and tear
• Enhance ergonomic comfort: Move freely with a smooth rolling surface for less stress on your legs and back
• Under desk coverage: Lip shape for extended under desk floor protection
• Easy to handle: Rounded AnchorBar cleats (studs) are gentle on carpets and hands (no sharp spikes)
• Clear Design: Made with clear vinyl to allow the beauty of your floors to show through
• No harsh smell: Made with GREENGUARD Gold Certified material to promote a healthier indoor workspace
• Made in USA