From my understanding the KJW Beretta's are a direct knock off of the TM M92's.
Can anyone confirm this?
Is such IS the case there are any number of internal upgrades available for the KJW Beretta. Such as the King Arms High Output valve found on Redwolf, which will fit different manufacturs M9's.
Found this thread on Airsoft Players that might interest you as well:
http://www.airsoftplayers.com/forum/...?TOPIC_ID=7611