ref: 10440's
i finally got my hands on Protected 10440's, i.e the Grey Protected Ultrafire 10440's. they are clearly over 47.00mm long and of very good built quality. good news is that i can get it easily running in my iTP A3 Titanium with the help of 2x 1.0mm thick copper sealing washers 1 of which sanded such that the cell fits through it; however as expected it's difficult to turn off the light because the Titanium head (which is naturally not-anodized anywhere!!) and the copper washers would get in contact with each other arbitrarily (because i didnt glue them to the PCB LOL) and thus cause a dodgy electrical contact.
And that contact closes the eletrical circuit and we get (continuous/intermittent) light, which we do not want when we twist off the head huh.
To remedy this situation you could buy the aluminum version of iTP A3 EOS because it seems to have anodized threads in the head yay, and gone would be the dodgy contacts! However (again), you would still have to use those aforementioned 2(!) washers because the Grey Protected 10440 UF's are over 47.00mm long. And using 2 washers on the iTP A3 (aluminum or titanium doesnt matter) is very silly because 1. the threads are short, 2. you're beyond the o-ring (water-resistant? not anymore, promised!), 3. the head is wobbly (guess why?) and tends to get lost easily. no no no. no go. So the bad news is i dont recommend using this particular cell product in the iTP A3.
You can still do it (e.g. like i do, with 2 washers) but the point is i do not recommend it, so better find some other way to use 10440's in the iTP A3.
Actually there are 2 other good ways!
way1. Find and buy Protected 10440's with a length of 46.00mm (or less) such that you need only 1 washer instead of 2. In this case use the sanded washer (and you better buy an Aluminum A3; the Stainless Steel and the Titanium versions will again produce the dodgy contact unless you glue the sanded washer either to the body or onto the (-)minus contact of the driver's PCB). Some German man reports that the Grey Protected Trustfire 10440 fulfills the 46mm-requirement. My personal evaluation: Since i own the Titanium version and prefer not to glue the washer to anywhere and dont trust the grey Trustfires, i will avoid way1 and choose way2 instead.
or, way2. Forget about the protection and buy Unprotected 10440's. Unprotected 10440's have a length of 44.0mm (as the name indicates), so you're all set. Take good care of the voltage with a multimeter or hobby charger. You dont want to overdischarge the cell because recharging overdischarged cells could..etc..
or, way3. take the ITP A3 head (aluminum or titanium doesnt matter) and screw it on a longer body. For example, i've screwed the titanium A3 head on the body of the Tank007 E09 (incl. 1 washer only) and since the E09's threads are soo looong, much of the E09's threads (plus the o-ring) do not even get "used". Interestingly, there is no dodgy contact phenomenon. While this works surprisingly well (i.e. no dodgy contacts yay) and is for sure preferable to using 2 washers, i cant recommend it either. An iTP head on a Tank body wtf?? That looks plain silly dude! And more importantly, since the head is not in contact with an o-ring, you can imagine ..etc..
Summary of this post ;), i have proven/confirmed that the trick with washers works okay in practice but is only recommendable if you have a 46mm-long Protected cell so that you're good with 1 washer only. (with 2 washers you'd lose touch with the o-ring, etc.) And in addition, this trick works best only with anodized threads, i.e. with the Aluminum version of the iTP A3. Alternatively, forget the iTP A3 and buy 2 copies of the Tank E09. The E09 supports Protected 10440's much better than the A3!!