This post lamp has one 3W super bright CREE LED and a 2.5 Watt monocrystalline solar panel to harvest the power of the sun. Has a built-in I/Off/II switch. During daylight hours, the solar panel will harvest energy from the sun, and store that energy in rechargeable Lithium batteries (included). At night, auto dusk-to-dawn feature will automatically turn post lamp switch on at I or II. Use switch position "I" for low output brightness. The lamp post will keep this conservation mode if no motion is detected. The lamp will light up to full brightness if any motion is detected and return to conservation mode after 30 seconds. Run time under this conservation mode is up to 50 hours hours. When the switch is set to "II", the lamp turns ON at maximum brightness, continuously, up to 10 hours, until the battery drains. Easy to install, no electrical wiring needed.