There are three types of Magicshine mounts included in this collection:
1) Handlebar mount, complete design, pinch-clamp
2) Handlebar mount, which uses a GoPro handlebar mount clamp
3) Helmet mount, which uses a GoPro helmet mount

I was tired of how the stock Magicshine 808 O-ring mount allowed the light to rotate while riding on rough terrain. So, I thought either a stand-alone mount or a mount using the excellent GoPro hardware would work well.

Handlebar Mount, Pinch Clamp
1) fasten the MagicShine 808 light head to the mount body using the a 4mm metric screw- take care to not use too long of a screw or else you can damage the light electronics. The stock screw might work.
2) use a 5mm Socket Head Cap Screw and 5mm nut to complete the pinch clamp

Both the GoPro handlebar and helmet mounts
1) fasten the MagicShine 808 light head to the mount body using he stock Magicshine screw screw. (which attaches the light head to the plastic O-ring mount)
2) use GoPro screw hardware to attach the mount to either the handlebar mount or the helmet mount.