KKMOON High Precision Voltage Reference Module AD584kH 4-Channel 2.5V/7.5V/5V/10V Built-in AD584-M, highest accuracy and stability. Same port can output reference voltage: 2.5v, 7.5v, 5v, 10v. The MCU switch 4-way reference voltage output with LED indicators. Single-button operation switch reference voltage output. Built-in lithium battery, easy to carry, can be charge by DC 5V, with charge indicator.