I recently bought one of those for $20 at Meritline.com
I had tried one of their bright green plastic cheapies ($13). That one had 2 seams across the double O-rings and an actual divot under one of them. I spent 20 minutes with fine sandpaper improving it. It worked but seeped a tiny bit on a dive. Not suitable for diving. The light was not as bright as the light being discussed and it has a broader beam. It measured 3W/0.84A with a fresh 18650.
This light has been on 3 dives and so far is fine. I did clean up the threads and O-rings before diving. The silicone O-rings are not top quality as 2 of them have a bit of a ragged seam. On the last dive with a fresh 18650 I compared it to my main dive light, a 5-LED canister driven by 2S2P 18650 Tenergy batteries. These are custom lights made by a local retired machinist. They are very popular in our murky NW water.
This light is a bit more focused than my canister light, and just about as bright in the focal area when fresh. I does fade with voltage drop and at the end of an hour dive it was slightly behind the canister. The whole light is actually a bit smaller than my canister light head, which is made from a modified D-Maglite.
Iām a bit concerned at the longevity of the switch. I rinse after dives and have been putting a little liquid silicone into it after it dries.
I just got a 26650 for it and have not done a dive with that yet. It should sustain the output longer.
So far Iām quite impressed.
Note-first posting.
Iāve been lurking on this forum for about a week having stumbled across it researching Lion batteries. Some are real junk. :Sp but you guys know that.
Iām mostly active in the RC and scuba communities. RC electric is heavily into batteries. Scuba is heavy into powerful lights. Thus my interest here.
Up until this light came up many of the ācheap Chineseā lights simply did not sound suitable for diving. Light reliability is critical in NW diving. But, for $20 I thought Iād take a chance based on the description and pictures. This thread was just too timely to pass up.