..if that works surely one could put a small round magnet on the inside of a rucksack's (or jacket's) fabric, and attach the light to the outside, right?
Nah it wouldn’t hold tina, not strong enough. I got these, they’re decent and can be found cheap, but as TM says, the magnet connects then you have to twist to fix it. Magnet alone would fall off in no time I reckon if there was fabric in between.
^
..if that works surely one could put a small round magnet on the inside of a rucksack's (or jacket's) fabric, and attach the light to the outside, right?