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 Size Information: the plastic washers are about 45 mm/ 1.77 inch in diameter, and the middle hole is about 5 mm; Sufficient to Use: you will get 400 washers for screws and nails, enough for your daily replacement and use in foam board insulation and other repair 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 Easy to Install: the round washer is easy to fix with screw or nail, and also you can remove it easily; The extra washers can be stored for the next time to use Colour:White Material:plastic Package Contents: 400Pcs x Plastic Insulation washers Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.