【Stable material】:Black rubber (extendable ball)ABS plastic (round card)Stainless steel (screw and round base.Excellent toughness,safe toilet cover,strong and stable. 【Universal hinges 】:Toilet Seat Fixing Screws are suitable for 14-18mm holes,perfect for broken or old toilet seat hinges. 【Easy to Install】:Universal toilet seat screws and bolts are easy to install, the installation process is convenient and quick, just push the toilet seat nut into the hole, put the washer and tighten the bolt from the top, the screw will expand and screw into the hole. 【Warm Tips】: Remove the old screws and bolts from the toilet seat and compare the size with the new replacement hinge kit. In order for your old toilet seat to work properly, the new part replacement must be the same size.