Material:PCB Resistor Board: This is the "resistor replacement box", a low cost alternative solution, you can set flexible and fast resistor between 1R and 9999999R, 1R step precision. For educational experiments, electronic engineering design or test clipping are great applications. Design based on the resistor series theorem. 1/2 watt tolerance +/- 1% SMD resistors. High quality FR4 fiberglass PCB. Maximum operating voltage: 200V colour: green size: 90 x 35 x 10mm Battery Undervoltage Control Board: Supply Voltage: 12V Electronic products: For STM Colour:Blue Size:40x29mm Package Contents: 1 x Battery Undervoltage Control Board 1 x Resistor Board Only the above package content, other products are not included. Note: Light 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. 2 PCS Electronic Accessories: 1 x Battery Undervoltage Control Board & 1 x Resistor Board Type: Electronic products Model Number: 12V Charging Controller Protection Board Application: Computer Operating Temperature: -40-+85