This cleaning block allows you to easily remove residue on your bonsai tools. Acts as a unique alternative to sandpaper, emery cloth, steel wool and rubbing compounds making it more gentle on your tools. Grit easily removes sap and other hardened materials on tools. Leaves a nice shine when finished. Embedded fine grit is perfect for polishing tools after removing sticky sap and caked on dirt/oil. Simply use block like an eraser, rubbing firmly on wet or dry surface. Made in the Germany. Non-toxic.