Reliable Material: These washers are made of polypropylene, a plastic material, featuring good insulation properties, low profile, and durability. Size Information: The plastic washers have a diameter of approximately 45 mm (1.77 inches), with a center hole of approximately 5 mm. Quantity: Includes 200 washers, suitable for general use with screws and nails in foam board insulation and other applications. Function: Designed for fixing and supporting expanded polystyrene sheets, extruded polystyrene, and various types of foam boards. Installation: The round washers are easy to install with screws or nails and can be removed as needed. Additional washers may be stored for future use. Color: White Material: Plastic Package Contents: 200 x Plastic Insulation Washers Note: Color appearance may vary slightly due to lighting conditions and screen settings. Measurement tolerance is ±1–3 cm.