We’ve improved this best-selling mat to make it more durable and longer lasting than ever before. The blue layer is 4 lb density foam which has a non slip surface that is resistant to wear and tear. The inside is white 2 lb. density cross-linked foam that provides superior cushioning for floor work. The mat is blue, and is available in 5/8" thick and 1" version for a more comfortable mat. Now with round corners. Ships oversize.  
Outside layer is 4 lb density foam which has a non slip surface that is resistant to wear and tear
Inside is white 2 lb. density cross-linked foam that provides superior cushioning for floor work