1. High-end technology MPPT solar maximum power tracking charging management chip, with trickle, constant current, constant voltage charging management 2. high-frequency low-conductivity internal resistance dual MOS tubes, high-current diodes, high-efficiency flat high-power inductors, alloy current detection resistors 3. The large-size aluminum heat sink at the bottom ensures long-term stable operation under high current 4. High-speed and efficient charging method 5. Dual status indicator lights, the red light flashes when the battery is not connected, the green light is always on, the red light is on when charging, it stops when it is fully , and the green light is on at the same time Input voltage: powered by a nominal 18V solar panel (recommended) Overcharge and float charge voltages are 14.8V and 13.55V, respectively Output current: maximum constant current 3A Working temperature: -40℃~+85℃ with overvoltage protection With MPPT function Colour:red Material:plastic Size: 4.923 x 3.437cm Package Contents: 2 x solar controller module 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.