File trays are available in various styles. There are single layers. multi-storey. Group and type. Wooden file tray: generally, it is made of boards, formed by woodworking machinery, and painted with bright paint. After assembly by small parts. There are upright. There are two types of iron file trays on the side: generally, the tubes are formed by pressing and painting. It can be positioned by small screws. Upright is more than upright. The file disk has a wide range of uses, and is simple to make, low in cost, convenient to use, and easy to promote.