Size Information: the plastic washers are about 45 mm/ 1.77 inch in diameter, and the middle hole is about 5 mm; Fixing and Supporting: these plastic washers are designed to use for fixing and supporting expanded polystyrene sheets, extruded polystyrene and many types of foam boards Reliable Material: these washers are made of polypropylene, a plastic material, featuring with good insulation, low profile and good durability, which are easy to hold Sufficient to Use: you get 200 washers for screws and nails, enough for your daily replacement and use in foam board insulation and other repair Easy to Install: the round washer is easy to fix with or nail, and also you can remove it easily; The extra washers can be stored to use, Weight: 0.7605948039 Pounds, Manufacturer: Reeatel