Material: High quality nylon expansion nuts and stainless steel screws are sturdy and durable. Screw size: 4.8*0.6cm. Nylon expansion nut size: 3.7 x 1.7 cm. Washer diameter: 1.4 cm. Set: The expansion nut set contains 2 stainless steel screws, 2 nylon expansion nuts and 2 mental washers. Easy Installation: Installation is very easy. Universal Fit: Stretch nut set fits most toilet seats.