Compatible with: Mechanic Box: Ver. 2 series (standard AK G36 etc.); Battery Voltage: 7.4 V - 11.1 v; Does not fit the next generation series; Contents: DTU instruction manual (English) / Supplementary instruction manual (Japanese). *Please read the QR code in the instruction manual to see the PDF in English.Use the translation app to read or incorporate a willish instruction blog or video for reference.Note: This product requires disassembly and processing of the mecha box is required for advanced users.We cannot support the installation, so please ask a custom shop for any concern.Be sure to read the instruction manual and make sure the sensor on your trigger, gear and selector will work properly in QUICK TEST mode.