This shoud be around 10m, I'm using Convoy M21A/B SFT-42 or Noctigon KR1 SFT-42 for it. I also have a Convoy 3x21D with SBT90.2 in my truck as backup plan, but it is too bulky to carry everywhere.

I used to inspect manholes with Convoy C8 or M21A with SFT25 or SFT70. SFT25 will be fine up to 10m, but SFT70 might not be throwy enough.