High-density sponge, full of elasticity, good resilience, the wet and dry sandpapers can fully absorb water, and better flexibility. -Material:Sponge,sandpaper. 1 x sanding block(60 grits) 1 x sanding block(80 grits) 1 x sanding block(100 grits) 1 x sanding block(120 grits) 1 x sanding block(180 grits).