Dura-Block AF4421 Hook & Loop Black Round Sanding DurablockGet an professional finish with top of the line sanding blocks from Dura Block. Great for wet or dry sanding, the blocks are made from patented closed cell EVA rubber. They are sized and shaped to create flawlessly flat surfaces and or detailed contours without ripples or gouging. The AF4421: 11? L, Thickness: 1 1 4? Versatile, flexible and conformable round (tubular) sanding block This allows the reuse of sandpaper and saves money and time.