TADAF4406 Features: -Precision Machined Block.-Hard surface tension.-Perfect for hard to sand areas.-Flexible - designed to fit a standard 9" x 11" wet or dry sheet of sandpaper.-PatentedThe "tear drop" adds a rounded curve with a flat surface for hard to sand areas. Designed to fit a standard 9" x 11" wet or dry sheet of sandpaper. Block dimensions allow for perfect fit for 100pct use of the sheet without cutting or tearing..-Dura-Block Tear Drop Sanding Block. Warranty: -Lifetime warranty does not cover abuse.