HIGH QUALITYToilet fixings are made of rubber and screws are made of stainless steel 304, much better than plastic fixings.SizeRubber Cover: 40mm/1.57", Metal Screw: 50mm/1.96", Fits Most British Standard Size Toilet Seats with Top Fixing Hinges. Fits 14 - 16mm holes.Easy to InstallThe rubber washers in the kit have threaded parts, so you just push them into the hole on the top of the toilet, when you tighten the screw, it will expand and screw into the hole by itself, no need for a bolt on the other end of the screw.Easy to useThe brass nut can be slip-proof and rust-proof. You don’t need to tighten the screws from the bottom with these toilet seat hinge screws. These rubber toilet seat bolts provide a lot of friction against the ceramic bowl holes, so they have an excellent grip compared to plastic.