Type:Shower door roller.wheel thickness :5mm,come with screws,suitable for 4-6mm thick shower door. Roller diameter: 19mm,Inner hole: 4mm, fixed with M4 screw. The pulley is made of copper +POM wheel, and the screw is made of stainless steel,corrosion resistance and rust resistance,it has good comprehensive performance. Pulley bearing capacity, good stability; Small friction coefficient, good mute effect. Easy installation, often used for bathroom glass sliding door pulley/sliding track.