I want some technical detail?

Maximum output power is 2.4W. Output voltage is 5V. Maximum output power is reached when the Sun is direct to the panel and low outside temperature. If the Sun and panel are under low angle or if there are clouds or some shade, transfer power is lower than maximum. Sun heat the panel and efficiency of panel decrees as the panel is heated. If used on the mountains where outside temperature is lower, efficiency is better. If used on the beach where temperature is higher, efficiency is lower. Why is it advertised 2.4W when it is hard to reach? When manufactures compare panels they compare based on maximum power point. What is the real power that I will get? On a daily basis you will be able to see 1.8W to 2W of power constantly generated. Is it enough? Yes, and you can always multiply by two, three or four times. With a multiplier you can get power equal to wall outlet power.