Material: The toilet seat extension bolts are made of high quality rubber and the screws are made of stainless steel. Stainless steel does not rust like metal, it is not easy to slip, it is not easy to break and its duration life is longer. Dimensions: The toilet seat extension screw is 4 cm high, 2.2 cm wide at the top and 1.3 cm wide at the bottom. Suitable for installation hole diameter 1.3-1.8cm. Nut type design: universal Phillips nut in a nutshell, providing you with great convenience, can be better installed and disassembled. Easy to install: Simply insert the toilet seat screw into the toilet mounting hole and tighten the screw. Convenient and time saving. Wide range of uses: suitable for toilets with mounting holes from 1.3 to 1.8 cm.