There are basically 3 kinds
1 - the old original manufacturer kind w/ black button, the manuals have a fairly open hole in the end 180/280/380mah
2 - the new original manufacturer kind w/ gold button also sold at the link above and by Vapor4Life in fancy colors, the manuals have a hole in the end that seems blocked inside 180/280/380mah
3 - the SmokelessImage/Bloogplanet/Halocigs G6 - the manuals are totally sealed and have a harder to press tiny partially recessed button, they claim about 40mah longer battery life but are .1 less in voltage (3.6 vs 3.7). These may all be rubberized too. These manuals may not work with the couple of kinds of so-called KR8 cartos that don't have a recessed slot across the carto post for airflow (like the Vapornine cartos and the LeCig D1 cartos which i didn't like anyway). The Boge and Vapor4Life and SI/Bloog cartos do have a slotted center post
I think my fave is #2. I enjoy my Volt manual but the button is a it hard to press. I won't buy autos. No matter how careful you are refilling cartos, occasionally one will leak and I like to not damage or kill batteries. Manuals also make it easier to get a good hit.
Note - the mega length ones may not fit in any of the PCCs - not sure if there is one that fits them.
if you want huge battery life, something like the leCig Pigcig, Cigeasy Elegant Easy, the KR8 threaded Kanger version of the Vgo, and I think the iGo provide fat battery solutions (should be 650mah and up)
