Coarse Grit Sandflex Bonsai Tool Cleaning Blocks From Hollow Creek Bonsai COARSE GRIT SANDFLEX BONSAI TOOL CLEANING BLOCKS Nol boo home or tox should be without this unique cleaning and polishing tool. Uses are endless from cleaning rust and tarnish from metal surfaces to polishing stainless steel sinks. Simply use the block like an eraser, rubbing firmly on the surface. The results are even more spectacular when combined with water, oil or any cleaning solution. You can "carve" the block to any shape to clean up a concave or convex surface. Made of semi flexible rubber compound with grits impregnated throughout the block. So, as you use it new grits are constantly exposed -- never dulls! 3" x 2" x.5" #1106 Coarse Grit