Featues & Benefits of 4x21 in Aluminum Oxide Sanding Belts. 6 Pieces X Grit 60 80 120. Heavy Duty X-Weight 100% Polyester Cloth Backing: Heavy duty X-wt gives the sanding belts a durable structure. 100% polyester material cloth features high strength, good elasticity, heat resistant, corrosion resistant, wearable and washable, which providing durability, longer belt life and the performance of standing up to heat sensitive applications.
eBay