They were added side by side. At first glance, you might be concerned about whether there is enough light. Well I promise you it's more than enough. I added two (one on each side) but actually one in the middle would do. It's kind of a "focused" beam, but it's pretty wide. It illuminates about 1 foot of the circle for every 1 foot of distance, and even ambient light is enough to find anything that isn't in the direct path of the beam. It has two different rubber backplates (flat or rounded) and Velcro if you don't want to screw the included screws into an arc. The rounded back is designed for a 2 inch rod. I don't think they attach well to anything less than this as far as attaching to the pipe.
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