My wife wanted to add solar lights to the edge of our Affinity Pool garden water feature. I created a two part bracket to clamp the lights in place on the edge of the pool. The design uses an M3 x 20mm bolt and an M3 nut to secure the bracket. The clamp part has a hex cutout to hold the nut in place. The example pictured was printed in Verbatim black PLA on a Wanhao D4S with a layer height of 300 microns and a 15% infill. No support is needed when printed on its side. The solar lights are of a type widely available in the UK from various Pound type outlets.