[Round Hinge Plate & More Stable]: The round hinge plate makes these toilet hole screws more stable, which is very suitable for use when your existing toilet accessories are loose. After installing these bolts, you don't have to worry about the toilet seat loosening. [High Quality Anti-Rust Material]: The expansion ball of the toilet seat bolt is made of high quality rubber and the screw is made of stainless steel, the brass nut inside the bolt is non-slip and rust-proof. Durable plastic round hinge plates will not rust and are better than metal washers.[Flexible Rubber Plugs]: The flexible rubber plugs slide perfectly into the hole, and when you tighten the bolts, they press into the hole to ensure a tight fit and make it easier for you to use the toilet seat.[Easy to install]: The rubber grommets in the kit have a threaded section so you can simply push them into the holes at the top of the toilet bowl and when you tighten the screw, it expands and tightens in the hole, without the need for a bolt on the other end of the screw.[Fits Most Toilet Seats]: Expansion ball diameter: 1.8 cm / 0.7 inch. Length: 4 cm / 1.57 inch. Suitable for 14-16 mm hole for 2 toilet seats. Ideal for broken or old toilet seat hinges. Fits most standard toilet seats with a top hinge.