Solar panel: Used to charge MP3 phones...pads or other controlled devices. Dual USB female ports, easily charge the device through the USB charging cable. You can put the panel in the sun and use it to directly charge the device. Suitable for outdoor cycling, mountaineering, hiking, camping, traveling, etc. Controller: Integrated industrial microcontroller. PWM load management is completely divided into 4 stages. One-key configuration, digital display, automatic memory function. Double mosfet reverse current protection, low heat generation. Short circuit protection, open circuit protection, reverse protection and overload protection. Solar panel: USB output: 5V Number of USB ports: double Solar panel voltage: DC12-18V Solar panel power: 20W Controller: Model: PWM Step-down charging: 28.8V Floating charge: 27.4V USB output: 5V / 3A Self-consumption: less than 10 mA Discharge stop: 21.4V Voltage: DC 12V / 24V Maximum solar input: less than 50V Current: 10A / 20A / 30A / 40A Nominal working current: less than equal 20A Disconnect and reconnect: 25.2 V Working temperature: -35Celsius-60Celsius Output voltage: 12V / 24V automatic identification voltage Suitable for 10V-12V photovoltaic system: 120W solar panel, 12V lead-acid battery, 21V, maximum input voltage. Suitable for 10V-24 V photovoltaic systems: 240 W solar panels, 24 V lead-acid batteries, 42 V maximum input voltage. System connection: 1. Connect the battery to the charge controller-plus and minus. If a 12V battery is detected, it will display 1; if a 24V battery is detected, it will display 2. 2. Connect the photovoltaic module to the positive and negative regulators. 3. Connect the consumer to the charge controller-plus and minus. colour:As shown Material:Polysilicon size:43.5 x 20CM Package Contents: 1 x 20W solar panel 1 x Solar controller (30A) 4 x suction cup 1 x alligator clip 1 x car charger 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.