Size:The toilet bolt screw is about 42.5mm,and the Nut diameter is 4.3mm.The fixing screws for the toilet lid are more secure than normal screws to prevent the lid from sliding and can be fitted to most brands of toilet lids. Material:The Toilet Seat Bolts and Nuts Kits are made of Stainless SteelSturdy and durable, and not easy to rust. Easy Installation : The toilet seat hinge screw kit includes all mounting parts:Toilet Seat Hinge Bolts with Plastic Plug ,Nut and Shim,When the toilet seat nuts/bolts are loose and not tight enough you can use this to replace the old one to use. EASY TO USE: toilet lid hinge bolts and screws are much better than plastic ones, use. Toilet lid hinge bolts made of stainless steel to replace loose bolts, the toilet lid won't wobble and the toilet lid nut/bolt won't be lost. Application: Universally suitable for the installation of toilet lids and the connection of all split toilet tanks and bases.