A&H Abrasives Black-Max ceramic abrasive pump sleeves give you better results with less labor and they last longer: Last up to 5 times longer than Premium Aluminum Oxide .Durable J wt. cloth backing for extended service life .Full Resin Bond.Anti-static coating reduces wood dust loading.J-weight cloth backing is super flexible for high performance pump sleeve applications.Ceramic abrasives are truly the carbide of abrasives.Available in the 3 most popular grits 80, 100, and 120 and seven sizes to fit most pneumatic sanders.Manufactured in Wyoming USA from components from USA and Germany.