These files are three different versions of a mount to attach a Magicshine LED light to a Giro Montaro helmet using it's included GoPro mount. This may work for other helmets and LED Lights, YMMV.
Rev 3 is probably the version you'll want to use, it places the light closer to the helmet and gives the most adjustability.
Note I have posted a few other Magicshine to GoPro mount helmet adapters:
Giro Edit: http://www.thingiverse.com/thing:684331
I used 0.2mm layer height and 70% fill with ABS. These parts are designed to print without support. You'll have to rotate the parts to lay flat on your print bed, typically either + or - 90 degrees on the X axis.
Designed using Solidworks 2016. I included both .STL files and the native Solidworks files for your remixing fun.