Well Nut Assortment 10 M4 M5 and M6 Wellnuts with Nylon Washers and Rubber Wellnuts, Great for Plumbing Water Craft Automotive and Motorcycle Repair, Fits Metric Screws, Home and Shop Repair Hardware Includes 10 M4 M5 and M6 Wellnuts with matching washers Wellnuts are metric threads Washers are made of an industrial grade nylon, Wellnuts are industrial grade rubber with a brass nut Great for mountings and hanging items around the shop and house Same hardware as used on many motorcycles and ATV's