Lupine Betty Lamp - mount for Troy Lee Designs - A2 Helmet

You need a Velcro Strap to mount the holder to your helmet. These Straps are usually sold to hold batteries on fpv drones.

I have also included a base plate design that could be used to design other mounts.

I've used this a couple of years with no issues. MTB rides. Roadbike rides. 

Additional tip for Lupine owners

I use cheap rc car batteries to power my lamp. They are cheap and are providing more current than the original 18650 based battery pack. I had issues with my original battery.