This is light weight piston which is made of Delrin. The end is made of SUS.
The Delrin has durability & its' very light material to pull easily & high power output at low tension Spring.
※ Actually,we have result that in case of low power Spring,Light piston's output is better than heavy piston.

This is built in the vacuum system to clear the negative pressure.
This couldn't stand for high power Springs.

※Please use the Spring which is Diameter : outer 13mm / inner 11mm. And we recommend VSR 110,VSR120
※For B↑Premier(HI-SP) Cylinder.This is not availavle with Normal diameter cylinder.

If you use power spring as SS,SPR or VSR high power spring,please select all metal piston. This has no durability using with their springs.

Vacuum system
Vacuum system is to let fly at BB more farther and go straight.
This system erase the negative pressure when shooting.The system is inside the head.
1.Conventionally,the valve is free in the system.(This is not air sealing)
2.When shooting,the piston go ahead.At that time,The valve closed & start to keep air sealing.
3.As well as the piston bump against the cylinder head,the valve come off.
4.The air flows toward top from rear.This cancel the negative pressure.