Bicycle Flashlight Holder for wowlight XML-T6

Attention! After a few days on the bike, the clamp for the flashlight became very loose. Currently, I am planning a better design. The screwed part that fits the handlebar is still sitting perfectly.

This is a thing to mount a Flashlight(wowlight XML-T6, I guess there are similar ones with different names) to a bicycle. It is supposed to fit to the thicker mid part of the handlebar, right beneath the stem. My handlebar has a 31.8 mm diameter at that point(should be 1 1/8" ?!). If your handlb