thanks f42 for the test. so can be confident to use this underwater.
now the promotion price is $29ish. if you willing to organize GB and get lower price, please let me know, I’ll definitely in 
thanks for the tips…when you do this, we take out all the inner parts or let them stay intact just like complete assembly?
Is this in reference to the hydrostatic test I was describing? If so, I just remove the battery, and of course make sure the cap is loose enough that when the air contracts in the host while it is in the freezer, there is more air able to enter. Then as soon as you take it out of the freezer, you screw the tailcap on tight - and of course when the host warms up the air inside expands and if there are any gaps you’ll see bubbles escaping. If you only get a bubble every second or so then the light is probably about IPX4, as I’ve had lights like that out in the rain for hours with no problems. If you get a non-stop steady stream of bubbles then it may only be ‘splash resistant’. As long as you have bubbles then of course no water is entering the light so no damage is being done. Just take the light out of the water before the pressure reverses the other way, but you’ll still have lots of time to assess the bubbles before you take the light back out. I’ve found that on some lights both switches and threads can be prone to not sealing all that well. If you test all your IPX8 rated lights this way, you’ll probably be suprised at how many actually leak and are really IPX4 or worse.
yes, I refer to your reverse testing.
many thanks for the detail, will try that
Just an update sorotantaz, and TSellers.
TSellers I didn’t use your technique to test but instead I used an air compressor 
…
Pumped great amount of air inside the light and air leaks around side switch just as sorotantaz said.
Out of interest, I just did a seat of the pants test of a few lights I had kicking around:
From best to worst:
Convoy M1 and Solarforce L2N: No bubbles after 5 seconds: I’d consider these IPX8
Spark SL6S (side switch and tail cap leaks), Solarforce P1 and P1D (tail cap leaks): one bubble every 5 seconds. I’d call these IPX4
Maglight XL200: 10 bubbles in 5 sec’s (cap).
and the worst: Convoy C8 and COnvoy M2: steady stream of bubbles from the tailcaps, too many to count.
It would appear that with the Convoy’s, it’s a game of Roulette with the tail caps. I must have got a good tail cap on that M1. I can say I don’t share Foy’s enthusiasm for the form factor of the Solarforce L2N, and the battery cavity is too big in it, but it looks like it is the most waterproof of the lights, the only one that matches it in my collection that I’ve tested so far would be a Spark ST6 headlamp.
Some questions:
1) It costs the double price of the convoy c8 2.8a, the l4 is the double better flashlight than the convoy c8 too?.
2) Wich is the use of the metal plate on the handle? I think with it is more complicated get the handle…
3) Will it have a group buy for the l4, at what price?
Thanks!
Thanks for the tests TSellers.
I think the price already good and it is better than C8, also didn’t see many people who wants group buy.
Tactical grip ring? It is preference.
Thanks for the review, making me want to get now.
what? So it does leak 
I just paid for 2 pcs few hours before
so can’t use this for snorkeling then.
anyway, can we remove the tactical ring? Is it plastic, rubber or metal?
What is the useful of the tactical ring? A better grip if you smack with the flashlight or what?
The ring was initiated on larger items originally to allow it to be used as a weapon by deploying it in a hammerfist strike, typically to gain time while tactically repositioning. That is why it is so silly on most of the present lights, but it does allow some light to escape from the bottom if you head stand it.
I think xatu might be referring to the ring near the on/off button end. I always thought it’s just to get a better grip for pushing the button in.
Ah thanks for clarifying. I didn’t realize that that end could also be called a ‘tactical ring’.
I have tail standing endcaps that have both designs and I have not noticed any difference in terms of pressing the button with my thumb. It does seem that the ‘tactical ring’ design however is less sturdy when tailstanding. The best tailstander that I have at the moment is the Spark SL6S that only uses a side switch.
probably the best $5 light in your bag….
You’re welcome troisanh.
sorotantaz, I pumped air with an air compressor from tailcap side and air leaks only around side switch, I did the test as soon as possible sorry
And you can’t remove it as you can see from these pictures.
xatu, you can check these websites for the use of tactical grip ring, I guess it can also be used for self defence too
Yes, i was imagining that, you strike with the head of the flashlight on something (selfdefense) and with that ring you can grip better the flashlight for striking/smacking/hitting.
I think that ring is worst than nothing because you can`t get the handle on all its lenght and the selfdefense with a flashlight… There are better ways.
Hi f42, I have another simple question. Can the generic C8 bezel be put on the L4? I am asking this because I wish to change the L4 bezel into C8 stainless steel one.
xatu, I think Convoy L4 feels better in hand especially just because of that tactical grip ring.
sorotantaz, you’re welcome, and it is really a must have light!
bibihang, Xintd v3 C8 bezel fits perfectly I do not have any other C8
And, I wonder how stainless steel C8 bezel will look on this light :quest:
Oh, i tought than the l4 had a bigger head and reflector than the c8 but it is the same!. Has the l4 better reflector than the c8, worth the money? It cost the double of a convoy c8… (Before much more)
