Material: The expansion nut is made of high quality stainless steel and nylon, which is used to fix the toilet lid and is durable. Set: the set of expansion nuts includes 2 × stainless steel screws, 2 × nylon expansion nuts and 2 × metal washers. Screw size: 4.8 * 0.5 cm. Nylon stretch nut size: 3.7 x 1.7 cm. Washer diameter: 14mm. Reminder: Please confirm whether the size is suitable before purchasing.