Carbide-RIFF Sanding Disc AVZ 90 RT2. Carbide Sanding. Grit 2. The Starlock AVZ 90 RT2 Carbide-RIFF sanding disc offers exceptionally long service life when removing mortar and tile adhesive. The disc is equipped with high-quality carbide grain of grit 20 for high wear resistance and thus an extraordinarily long lifespan. The open coating allows for aggressive material removal without clogging or buildup, resulting in a longer lifespan for the disc. The delta-shaped disc can reach hard-to-access corners. It is ideally suited for removing mortar and grout, carpet adhesive residues from mineral surfaces, and for rasping wood for coarse shape adjustments. It is compatible with all Starlock, Starlock Plus, and Starlock Max type power tools, as well as all common multifunction tools. The attachment system allows for maximum power transfer between the machine and accessory due to its three-dimensional tight fit.