High quality Toilet fasteners are rubber, screws are 304 stainless steel, much better than plastic fasteners. Size Rubber sleeve: 40mm / 1.57inch, metal screws: 50 mm / 1.96 inch, fits most UK standard size toilet seats with top hinge. Suitable for 14-16mm hole. Easy to install The rubber eyelets in the kit have a threaded section so you can simply push them through the holes at the top of the toilet bowl and when you tighten the screw, it expands and tightens in the hole, without the need for a bolt on the other end of the screw. Works great Brass nuts can be slip resistant and rust proof. You don’t need to tighten the screw from below with these toilet seat hinge screws. These rubber toilet seat bolts provide great friction against the holes in the ceramic bowl, hence excellent grip compared to to plastic. Package includes 4x rubber cork, 4x metal washers, 4x washers plastic, 4x screws.