Fps Ergal cylinder set for AK47/74 short barrel electric gun

New improved set with ergal dual oring piston head with ball bearing
hi drain cylinder head with enlarged oring 
ergal nozzle with internal oring included
steel polished hi pressure cylinder 
suitable with 201mm at 250mm
this set will enhance the accuracy and shooting performance

for Marui AK47/74 electric gun series and compatible