Welcome!!
You can get into a lot of trouble looking around the internet. Sadly there are a lot of rip-off rebranders.
Here are some tips
If they don't sell blank carts or cartos for it, then walk away
If they say a cart lasts the same as a pack of cigarettes, walk away because they do not
If a battery costs more than $19 then walk away
Don't buy at a mall or
tobacco shop
Don't buy something the length and diameter of a king cigarette aka a super-mini (unless you want to buy something else 4 weeks later)
Don't buy anything of you don't know what model it really is, whether it is a good model, and whether you are paying too much
And don't sign up for a free trial of anything
The basic starter models are these 3 and the fat battery versions of the same. The basic versions are about 120mm long and a bit thicker than a cigarette. The basic models have short battery life (though the KR8 is a longer charge for the same overall length because it is a 2-piece). The fat models have much longer battery life and enough power to use some lower resistances attachments which can provide bigger hits.
Joye 510 (fat is Ego, Riva 510, and some others)
DSE901 (fat is Riva 901)
KR808D-1 (aka Vapor King at Vapor4Life) (fat is CigEasy Elegant Easy and Bloog might have a fat battery version)
there are also some slightly less popular and less flexible models that are still good
beyond that there are a variety of exotic mods and high-power mods
The main research you need is in the sticky threads of new members:
1. newbie Videos
2. thread with Library in its title leads to an illustrated guide
See which of those 3 models I listed appeals to you or maybe something else will. You need to figure out if you think you want cartomizers or carts. 510 is a cart model with lots of blank cartos available and many adapters available for other models' atomizers. 901 is a softer hit but tasty cart model is maybe a couple of kind of blank cartos available, some adapters may be available. KR8 is a cartomizer model only with a variety of prefilled and blank cartos, and you can instead put a 901 atty and 901 carts on it (or 510 atty/carts with an adapter)
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re rush - tobacco doesn't give a rush as much as the fact that you are breathing CO2 and carbon monoxide and 4000 chemicals including toxins. You won't get the same kind of rush from an ecig. And you'll have to find a tobacco juices that you like on your ecig.
BTW Greensmoke is an ok unit but it is the less popular of the KR808D's - it is the KR808D-2 aka e9, a popular rebrander 2-piece. The -2 is popular with rebranders who put their own name on it and often sell harder to refill cartos. KR808D-1 is a more common recommendation here - it has different threads and is the more supported 2-piece for adapters etc, fat battery models, variety of refillable carto types, etc.
