Used to protect delicate material such as natural stone or glass from scratching when used the Perfect Level Master wedge and clip leveling system. Goes around the leveling slip and sits between the wedge and tile when installing. Bases are fully reusable. Also works as a grout spacer with 4 different widths - 0.5 mm, 1 mm, 2 mm and 3 mm. Can also increased the wedge height when installing thin panel tile.