Product Feature: 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 drop in pressure or decrease in air consumption . 4. There is large valid area of section. 5. The spool is made of [...]