50mm Medium Surface Blending Quick Change Discs. Non-woven abrasives for cleaning, finishing and polishing operations. Non-woven abrasive is of an open mesh construction, waterproof, washable, resilient, conformable, non-loading, non-conductive, non-metallic and non-rusting. Achieves a good medium finish. Best choice for controlled results on softer materials, or expensive alloys. Features: Quick change fastener Twist on and twist off available with a male thread. Twist on and twist off threaded discs are equivalent to 3M™ Roloc™ fastening system. Benefits: Quick, tool-free disc changes allow for more grinding time Disc locks securely to back-up pad, but is easily removed Mount to the appropriate Quick Change back-up pad Discs can access restricted corners and contours Price per 25 discs.