A Favorite Among The Professionals When Blocking All Surfaces. HIGH END PROFESSIONAL SANDING BLOCKS FOR SHOW CARS AND PERFECT FLAT FINISHES (THE BEST SANDING BLOCK MONEY CAN BUY). The Dura-Block enhance any project you're working on and are the ideal solution for Classic Car Custom Restoration, Boats, Planes, Trucks and many other projects requiring absolute perfection. Made of 100% EVA Rubber. Use for wet or dry sanding