kimsun slim 2r is a really good choice for advanced vapers - not just an ecig, but as well a dry leaf and vax vaporixer. This e-cigarette works like a beast - so much vapor and such a long battery life. This is a bit more advanced technology - they are using mini-tanks and you can see how much liquid is there left in the cart. On the battery you can see how much power it has left. Vapor amount of eleaf icare 2 kit is amazing, flavors are great. Price is a bit high though.