【Sliding Wheel Slides】 The wheel of the door roller is made of nylon plastic, which is resilient, with low friction and low noise, works smoothly and easy to slide. 【Durable Material】The main body of the shower door rollers is made of 304 stainless steel, which is durable, wear-resistant, not easy to break and not easy to rust. 【Door Roller Set】Shower door roller set includes 4 bottom rollers, which exactly match the installation requirements of two doors in one bathroom 【Glass Door Roller】 The door wheel rails designed for 5mm or 6mm glass doors, and perfect for most shower rooms, steam baths and kitchen doors. 【Detail Size】: The door rollers are a practical accessory, you can attach the centre of the screw to the end of the roller: 18 mm. Roll size (diameter x W): approx. 25 x 5 mm/0.98 x 0.2 inches., Manufacturer: Raguso