ZERO upgrade set for CM.703, CM.707

Durable and light upgrade set for CYMA CM.703 and CM.707. Package include all what is needed for basic upgrade. Hybrid Piston The piston is made by CNC machining from light, but durable aluminum alloy 6061-T6 (Dural) with a high-quality anodized finish. The piston catch is made of stainless steel. The piston has two sliding polyacetal (POM) rings. The piston head has an back-pressure system with O-ring (O-ring expands and seals better when shotting). The enlarged inner piston diameter allows you (and we recommend) to insert a stronger 9mm spring upgrade . Dimensions : lenght - 76,8mm, outer diameter - 21,8mm, inner diameter - 13,5mm Weight : 28g Spring guide Allows the use of classic 7mm springs and stronger 9mm spring springs. Axial bearing makes pull back much smoother , because of limited spring rotation. The spring guide is made of stainless steel with a perfectly smooth surface . Spring High-quality spring made of spring wire with heat treatment and grinded ends. Chemically blackened against corrosion. The outer diameter of the spring is about 12.8mm. Springs are offered in range from M140 to M160. You can simply select it before add into shopping cart. APPLICATION: Set is dedicated for CM.703 and CM.707 , but you have to use OUR CNC trigger mechanism.