Widely Used: Toilet Seat Bolt Expander Ball Diameter: Screw Rod: 304 stainless steel, external thread: 6mm (M6), length: 50mm; seal: 304 stainless steel, outer diameter: 18mm, thickness: 1.5mm Expansion Nut: Copper nut embedded in NBR rubber. Ideal for damaged or old toilet seat hinges. Fits most standard toilet seats with top fixed hinges. Made of rubber and metal, better than most plastic fasteners on the market Overview: High quality material Black rubber (expander ball)/Stainless steel (round card)/Stainless steel ( screw). Toilet seat bolts are made of solid metal hinges and bolts, better than most plastic fasteners. Easy to install: The rubber washer in the toilet spare parts kit has a threaded part, so you can push it into the hole at the top of the toilet. When you tighten the screw, it expands and tightens in the hole without driving another bolt. The end of the screw. Packing List: 2 Single Balls + 18mm Joints (1 pair of 2) We only sell the first item in the picture, not