The 306 have a smaller diameter. Makes for a hotter more intense experience.
The 2.5ml is the juice capacity. Basically these are the size of a 801 atomizer.
The New 3.5ml Clear Dual Coil has landed at COV. Awesome Capacity and Clouds of Vapor!! By SMOKTech!
I got the 808 duals and punched one and put into my AFS2. WOW!!! They are great. My fav carto now for the AFS2.
I will have to try this...How many holes are you punching on these Captian ????