4-72风机系列图纸, 包含A B C D型 外形尺寸齐全，内部结构图等全部都有-4-72 blower series of drawings, including the Dimensions of ABCD is complete, the internal structure of the map have

C#自定义控件，可以显示DXF文件，支持多张显示（合并为一个图）。(C# custom control, you can display the DXF file, support multiple display (merged into a map).)