No prob at all. I would think the EFEST is a SANYO re-wrap, same with the iJoy 20700. But the EFEST is in stock, the others aren't. The lengths are listed dead-on, and the weight of the EFEST and iJoy are dead-on.
The Efest is metallic purple , I like em! 
I doubt that the iJoy is a rewrap of the Sanyo 20700. Probably a Chinese cell (maybe Lishen??).
See: iJoy 40A 3000mAh 20700 Bench Test Results...overrated but a good 30A battery | E-Cigarette Forum
Mooch, over at the e-cig forum, has a set he is testing now.
Here are the results:
It say’s JAX6G70406 on the IJoy battery, wrapper says cell made in Japan?
A comparison, at 30A, of the iJoy 20700 vs Panasonic/Sanyo 20700A can be seen here:
http://www.mountainprophet.de/forum/viewtopic.php?f=16&t=1023
The 20700A is the winner.
I run the 20700A’s and IJoys in my JAX X6 Hunter with the new 70.2 P2-1A and both pull 20amps, I don’t see any difference? Now you can’t get either? Hopefully the Efest can perform the same, I’ll see when I get them…
that efest is a chinese cell.
its not a bak,dlg,yiklik,or lishen unless they just forgot to update their webpages.
From the discharge tests it looks like the ijoy and 20700A cells have similar IR, so would give the same current in a direct drive light, but the sanyo has a bit more capacity.
I’ve been an Efest user for quite some time now, looking forward to seeing how their 20700 stacks up…
Got my two Efest 20700’s in today. The new style metallic dark purple with 30A continuous rating and 3000mAh capacity. They aren’t “re-wrapped” anything, as the wrap is semi-transparent and you can easily see the metal canister. Charged them at 1A charge rate and in my DBC-05 Triple XHP-50.2 they give 24.90A for 12,523.5 lumens! (start, after the amp reading and a first read)
That’s over 500 more lumens than the Sanyo 20700A’s Tom is letting me try! Amperage is slightly more, up from 24.40 to 24.90A. Tom’s 2 20700A cells did 11,833.5 lumens. For a first look, these are proving out quite well!
Edit: Checking these Efests against the two varieties of Sanyo that I have, the internal resistance (according to my Opus C3100 v2.2) is a bit lower on the Efests showing 39 and 41 where I get 42 and 45 on the Sanyo A cell. Also, I had bored out the tube on an older Convoy C8 with threaded pill and have a Sanyo 20700B inside, it’s snug but it does slip in and out. The Efest 20700 won’t even begin to fit. The Sanyo’s measure 19.9-20.0mm while the Efests I just got measure 20.3mm… again the wrap is a semi-transparent metallic purple that you can clearly see the insulation disc through on the top, as well as the lines of the canister at the top end, it’s not a double wrap at all. The Sanyo 20700B and 20700A both have a triple flange cap on top, the Efest has a 5 flange top, nothing like the Sanyo’s on the positive contact plate.
There is no efest or ijoy 20700 cells, we all know that.
Important!
Those are not rewrapped Sanyo/Panasonic 20700A cells.
Efest and Ijoy are using leftovers made for one customer by Chinese Moli manufacturer.
Grade B or C.
You will notice huge inconsistent cell to cell performance.
About that (I think they call him Mooch) test guy from ECF.
IMHO he is just trying to push sales and help Chinese (probably some deal between them)
There is NO 30A Sanyo/Panasonic 20700A on the market.
Good luck.
Regardless who’s making them, they still out perform my best 18650’s and 26650’s for out put. I have all 3 makes, Sanyo’s, IJoys and Efest there all pretty close to each other as far as performance, pushing my FETDD modded lights to the brink! In my case that is all I care about, thanks for the heads up!
The 2 Efest 20700’s I got pushed my DBC-05 to new levels, besting the 12,000 lumens mark I’d been hoping to cross with no luck before these metallic purple cells came along. Results, the name of the game…
I think it is useful for community to know who actually made them (many pple were asking)
So again it is manufactured by Moli / Grade B or C cell/ .
Some of you will get very good performing cells, some less fortunate folks will receive not so good performing cells (under the same wrap).
Waiting for NCR20700C. That should be very interesting cell to test.
So where are you getting this information? I’ve had the original Moli cells and they suck. My new Efest 20700’s have the highest output and current of any cell I’ve tested in this triple XHP-50.2.
Exactly.
Read my comments.
Some will suck some will work just fine.
I am working with batts for almost 10 yrs so let’s say I know each and every brand and what cells they are using.
Efest, (all chinese) will rewrap whatever they have on hand (whatever they have on market for lowest price), the first batch is usually double tested and carefully selected.
Once good folks like you, and test boys give it a “green light” then it is time for a little Chinese game called ” wrap anything as long as size is correct and ship it” 
Totally have to disagree with ya on that Space Cowboy.
It is your right to disagree. I am not here to argue at all.
I am providing info that might be useful for new (and usually naive) community members.
For me personally supporting Efest, Imren (BTW own by the same guy) who built their brands by cheating and injuring people (Vapers) is quite unethical. Again, that is just my opinion.
Just do a little research online and you will see how 5 Amps cells were magically transformed to 30A, 40A cells by Efest, Imren, MXJO……
Vaping community catch them multiple times switching cells from good to really bad and dangerous.
And that is exactly how they’ve made $$$$.
By cheating naive vapers.
But only 0.01% of people reading this anyway, so good luck to all.
Another info that I forgot to mention: These Moli cells will run out soon, so you better buy now before they switch to “higher” grade 20700.
Same applies for NCR20700A.But, I think you will not find ncr20700a anyway.