Features 1. The rubber grommets in the kit have a threaded section so you can just push them into the holes in the top of the toilet pan and when you tighten the screw it expands and tightens itself into the hole, without the need of a bolt on the other end of the screw. 2. You don't need to tight screw from bottom with these toilet seat hinges screws. These rubber toilet seat bolts provide great friction against the ceramic bowl holes therefore excellent grip compared to plastic 3. Toilet seat screws and fixtures are made of high quality rubber and stainless steel, sturdy and durable. 4. The rubber bungs slide into the holes perfectly and when you tighten the bolts they squash up in the holes to make a good tight fit. 5. Quality Guarantee. We have faith in our product and always back it up with trustful customer service, please reach out to us if you have any questions or problems about our products. Specification Material: Rubber+Metal Color: Black Package Includes: 4 x Rubber Washer 4 x Metal Gasket 4 x Plastic Gasket 4 x Screw Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-YJL official store