Upgrade kit for CM.703/CM.707 rifle AirsoftPro

Upgrade kit for CM.703/CM.707 rifle AirsoftPro, package includes all parts for a basic upgrade.
Hybrid Piston
Made at precision CNC machines from durable and lightweight aluminum alloy: 6061-T6 (Dural) with anodized finish.
The piston catch is made of stainless steel.
The piston has two sliding polyacetal (POM) rings.
The piston head is provided with a back-pressure system with O-ring (it expands and seals better)
The diameter of the piston is enlarged to be able to mount stronger 9 mm upgrade springs.
Dimensions:
Length - 76.8 mm,
Outer diameter - 21.8 mm,
Inner diameter - 13.5 mm
Weight: 28 g
Spring guide:
It allows the use of standard 7 mm springs, but also 9 mm upgrades.
Made of stainless steel with a smooth surface.
Axial bearing makes pulling back much smoother, because of limited spring rotation.

Spring
Made of quality heat treated wire, polished to the end and chemically blackened to withstand corrosion.
The outer diameter is 12.8mm.
The package includes M160 spring

Compatibility: sniper rifles CM.703 and CM.707, but used together with the trigger mechanism dedicated to this type of upgrade code: 9958.