I started with two, which I installed on the front of the house's gutters. Although the low light is useful, the full light is as bright as a regular lamp. I have a sidewalk outside my driveway, and the light would frequently turn off due to automobiles or people, and the gadget had no adjustability, so I used a piece of cardboard to cover the top of the sensor, and it now works well. It's summer, and it lasts all night on the dim setting, with 15 seconds of full for each movement. So I went outSee full review