From the manufacturer:

How many times have you lost dice or had to re-roll when the dice fell off the book or table? Do you prefer to sit on the couch or floor on game night? Need a convenient place to roll your dice? Then the DiceMat(tm) is for you! For use with any RPG, miniatures game, wargame, or board game that uses dice. Sturdy matted 8X8inch rolling surface and 1inch high walls are perfect for those expensive dice and reduces rolling noise, great for playing in public. Say no more to lost or errant dice! Perfect for the player, keep those dice in line! Perfect for the GM for secret and key rolls.

This unit has been used, and there is some wear on the dicing surface (felt). Still fully functional. The DiceMat measures 9.25 inches square, the dicing surface is 8 inches square, and it's 1.25 inches high. 

Adult use in a smoke free household.

Thank you for Looking!