The rubber grommets have a threaded section. When you tighten the screw, it expands and tightens hole without the need for a bolt on the other end of the screw Made of stainless steel and rubber, strong and durable Top fix: you can attach by pressing down from the base with a screwdriver. Save time and effort The rubber plugs slide perfectly into the holes and when you tighten the screws, they press into the holes for a good fit Ideal for broken or old toilet hinges. Fits most standard toilets with top mounted hinge, Manufacturer: Vdaxvme