I'm not sure if there is a True 3.0 ohm Boge Carto.
All the ones I have ever seen are listed as 2.7~3.0 ohms.
FIVE (5) Joye 510 compatible e-Cigarette blank cartomizers (Manufactured by Boge)
With the exception of the ones in the link I provided: 3.0 +/- .1 ohm assuming they are genuine....all I know is they work well. If my darn Radio Shack digital didn't break I'd check the ohms for ya'll. If I pick up another meter I'll check them.