Reapers Airsoft combs through the Jefftron Leviathan V2 Optical MOSFET with Real Feel Speed Trigger (RFST) in this video review... "Hi! Hi! In this video we install the Jefftron Leviathan V2 Optical with Real Feel Speed ​​Trigger and take a look at the app in detail. The EFCS is installed in my Burk BR10 AEG."