1. There are many port sizes: 1/8″ 1/4″ 3/8″ 1/2″ 3/4″ 1″.
2. It allows the fluid to flow in one direction ONLY.
3. It is prevent backflow due to sudden in pressure or decrease in air consumption .
4. There is large valid area of section.
5. The spool is made of POM valve´s core sealed with rubber and it has a compact structure.