No matter how you hold them, these sanding blocks are comfortable in your hand. Set includes: Six 5" blocks of three different densities vary in firmness with soft, rounded edges virtually eliminate gouging. Every single curve and surface on each block has been designed for a purpose. The tapered edges allow you to sand up to and underneath hard-to-access areas. The Corner-N'-Cove block with its offset handle allows for a clear view of the surface being sanded. Designed to work with any adhesive backed sandpaper, we recommend a specially formulated adhesive, cloth-backed Super-Flex sandpaper. This super flexible J-weight sandpaper is extremely pliable (it's been pre-flexed) and will not tear or crack while being applied. It doesn't load up and lasts 5 times longer than ordinary sandpaper.