Size: Expanding Ball Diameter: 1.8 cm/ 0.7 inch; Rubber Fixing Length: 40 mm/1.57 inch; Screw Length: 48 mm/1.89 inch. The pin entering the seat is approximately 8 mm in diameter. 14-16mm hole for toilet seat. Note: Before placing an order, please check the product picture to confirm the specification and style, and confirm that the height and diameter of the column are consistent with the style you need. The main difference is the notch, height and diameter on the plunger. Premium Quality: This toilet seat top fixture is made of stainless steel and plastic, it has excellent toughness, strong, stable and durable. The rubber stopper slides perfectly into the hole and maintains a good snug fit when tightening the bolt. Easy to Install: Easy to replace, no need to go under the seat, tell to keep tightening the nut. In just a few minutes, the seat is securely held without any wobble. Wide Use: Specially designed for toilet fixing brackets, it fits most standard toilet seats and top fixing hinges. Great for broken or old toilet seat hinges.