You don't know where to put your SERAPH engine? M4 or AK?
 
Need a new wire harness for your Polarstar HPA engine?
 
Get an additional wire harness so your engine will be ready for any V2 or V3 gearboxes!
 
Wire harness length:
20cm: if you want to put your FCU in your grip, or put your FCU in your AK handguard,
30cm: for V3 (AK) and V2 (M4) with short/collapsible stocks,
40cm: for V2 (M4) with standard buffer stock length or full-stock (like M16).
 
NOTE: 
All wire harnesses for the SERAPH HPA engine are compatible with PolarStar electronics: same connectors, same pinout.