Light and medium mobile shelves, also known as shelves, light, medium shelf rack evolved, dense structure, only need to set up a channel ( 1m around wide ), good sealing performance, beautiful and practical, safe and reliable, the highest space utilization of a shelf, manual and electric two types. Rail can be embedded into the ground or installed in the ground, shelf base moves along a guide rail, rack mounted on the base, through the sprocket drive system so that each row of shelves easily move smoothly, the goods by artificial access. Mainly used in archives, library, bank, enterprise data room, electronic industry.