Diablo's premium corner contact sanding sponges include break-through innovations for superior sanding performance extended sanding life and increased hand-sanding productivity. 100 Grit Fine Angled Sanding Sponge The superior grain bonding system Endura-Bond provides Diablo's sanding blocks with longer life and extreme durability. Featuring a premium aluminum oxide blend these dual-edge sanding sponges remove material faster and offer up to 3X longer sanding life versus standard hand sanding sheets. 5 in.