[OBD2 expansion box] BX100 is a universal diagnostic tool suitable for 12V/24V vehicles. [Constant Voltage ECU Programming]Equipped with a dedicated "CV" button to provide a stable 13.8 V output, ensuring reliable power supply during ECU programming and avoiding failures caused by voltage dips. [Real-time pin voltage display]Equipped with a digital voltage screen, it accurately displays all 16 pin voltage values (accuracy ± 0. 1V). Automatic warning of abnormal voltage (too high/too low) to quickly locate fault points. [16-pin OBDII interface & 4mm banana socket]The expansion box completely replicates the standard OBDII 16-pin layout, adapts to any specification of 4mm banana socket, and can be conveniently connected to multimeter, oscilloscope and other test equipment. [Built-in safety protection and intelligent alarm]Equipped with multi-status indicator lights, audible and visual alarm, overload protection, short circuit protection and reverse polarity protection functions. Supports the power battery life function when replacing the car battery. Key point :for 12V or 24V vehicle system!!! Plug-and-play design to diagnose communication faults, prepare the scanner for use or perform advanced ECU programming. Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.