I use a custom bracket and some hose clamps. long story though. It’s not very heavy, so I think a twofish mount would work on the G20 quite nicely. I was saying it might not be quite enough for a TK35 though. I’d have to estimate the battery live of the G20 at maybe 2 hours average and up-to 4 depending on how I’m using it. I never run it full turbo most for more that a minute I would say. It’s been long enough for me, when I’m using that one it is often very dark.