The ICS Polycarb Piston and piston head set is very light and very strong combo. Polycarb pistons are great for keeping a lightweight power train that won't damage the gearbox shell, but at the same time remain strong enough to hold up with mild upgrades. ICS designed this piston to be used with their stock springs.
The use of aftermarket airsoft parts is not an exact science. Some parts may require fitting even thought they were designed to fit without modification. Professional installation of upgrade parts is highly recommended.
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