Material: The expansion nut is made of stainless steel and high quality nylon, which is used to fix the toilet lid and is durable. Set: The expansion nut set contains 2 × stainless steel screws, 2 × nylon expansion nuts and 2 × metal washers. Screw size: 4.80.5cm. Nylon expansion nut size: 3.71.7cm. Washer diameter: 18mm. Warm reminder: Please confirm whether the size is suitable before purchasing.