Ok I know we all been there
Go into a shop ask for specific coils only to be told sorry we don’t have those in stock grrrr so then becomes a mission trying to find a shop that has them in stock
So I stopped relying on shops and order online so as not to be left high and dry.
Also here in the UK there is not as many vape shops as there used to be.
But as a let’s say i am a seasoned vaper I use two devices at one time one on charge one in use or when outdoors ones empty or power low I switch to the other so never left without.
I used to make my own coils and gave up due to laziness and time constraints I found it easier to just pop in a custom made coil specially due to being actually able to taste flavours thanks to the awesome gtx coils, life was sweet.
I was sent 2 rbas (rebuildable tank atomisor) I thought oh not getting into that again,
But it was my duty to inspect and try these tanks of which support single or dual coils first impressions on inspection were positive pretty impressive to be honest flat build deck as older versions used to have posts restricting space on deck and airflow pins and used to be massive tanks 28mm and above This was 24mm and would fit most small mods
The supplied coils were yuck 
not to my preference slung over shoulder into the abyss I purchased pre-made coils that suited my preferred wattage as to try and match the astonishing vaperesso gtx coils for flavour but sadly flavours can drop off quickly in a custom coil in a few days so let’s see if diy coils are better.
Can I say wow the flavour and ease of build.
For the single coil was spot on
the dual coils set up wasn’t impressive to me it gave bigger clouds less flavour used and more wattage and more battery drain I had to purchase smaller diameter coils for this kinda setup, Single coil was better suited.
It seems rebuildable tanks are becoming more popular of which can suit many for loads of reasons
First reason being costs let’s break it down I use two devices at one time so when one shows 2000 puffs I change the coils in both which is the normal weekly ritual stripping down devices for hygienic clean and replace coils.
This then works out at nearly 2 packs of coils a month 5 coils per pkt at hmmm £9.99 a pack so annually that’s just under £240
Buy a pack of rebuilt coils 10 per pack at £9.99 plus a pack of 40 cotton laces £4.99 that’s annually £15
So a saving of over £200 annually and
Can save more if buy rolls of wire and make own coils. And never be without a coil.
As each coil can last upon research can last up to 2 month or longer you just need rewick ( replace the cotton) clean coil brush off gunk and rinse with warm water.
So those on a tight budget these are definitely recommended.
But for me I will stick to custom made coils it is simpler and quicker as I don’t have the time. Or maybe keep my rba and mods for outdoors due to the massive clouds these chuck and use the lux max or xcross pro 2 for indoors for stealth vaping. Time will tell or keep them ready for when online shops are out of stock on my fave coils. The options are endless 
I found these tanks louder on inhale like your Darth Vader trying to breath or an old whistling kettle saying your water is boiling but great quality build no leaks and loads of fun making own coils.
Mesh coils are better than wire coils for flavour due to more even heat but for mesh rbas these had to many issues as the mesh sheet was just an arch and cotton fed underneath so had to be right thickness against the mesh but once saturated the cotton would go flat away from mesh arch so would create inconsistent heating there is now spring loaded decks pushing the cotton tight against the mesh if you’d prefer a mesh rba instead of standard wire coils. Make sure your choice includes spring loaded decks rba.but I’d recommend the wire coils.
Nowadays it’s all about size being compact but these tanks are small and paired with the new Armour Ultra… it would be a marriage made in heaven for those who venture into Rba
For a perfect combination.
