Material: Toilet seat hinges top fixings are made of high quality nylon expanding nuts and stainless steel screws, sturdy and durable SizeScrew size is 4.5*0.6cm/ 1.8"*0.24", nylon expansion nut size is 3.8* 1.4cm/0.15"*0.55",diameter of washer is 1.4cm/0.55", universally fit for most toilet seats Design: 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 Funtion: Top fix toilet seat fittings are used to fix the toilet cover, Plastic washer will not rust like metal, brass nuts can antiskid and antirust PackageExpansion nut set contains 2 pcs stainless steel screws, 2 pcs nylon expansion nuts, and 2 pcs mental washers Material Plastic Item Weight 30 g