I built these backing plates so I could use double sided tape to mount a set of Linkitom LED flashers on a mower without having to drill holes. The backing plates get attached to the flashers using M4 cap head screws (8mm - 10mm). Reliefs in the backing plates allow for routing of the wiring on the surface without having to drill a hole.
I plan to use servo tape (aka Alien tape), but double sided automotive trim tape should also work.
The flashers I am using are these: https://www.amazon.com/dp/B0DJ86PKTH but there are other products being sold with what appear to be the same form factor. See picture of dimensioned sketches for measurements.
Fusion 360 and .STEP source files are included as well as .STL
The author marked this model as their own original creation.