This is a door wheel with a soft-motion feature. The total length of the product is 138mm. The dimensions of the door wheel's mounting section are 42.8mm in height and 38.4mm in width. Please refer to the images for details. This door wheel is for hanging sliding doors. It consists of a component with two wheels integrated and a component that supports it. Although it is a new, unused item, it has some minor dirt because it was taken out of the box. I bought it for over 10,000 yen as a set, but I'm offering it to someone who can replace it themselves.