Hi, New here and have been looking around the forums for a bit which helped me make a decision on which e-cig to buy. I ordered a PCC and a shorty battery from Vapor4Life. The package works great and they threw in a few extra cartomizers with my order, so thank you. I recently ordered a batch of blank cartomizers from elsewhere that are supposed to be compatible with the Vapor King batteries. It seems like the Vapor4Life cartomizers have a groove cut out in the center. Is this to lock users into using their cartomizers? It costs just as much money for Vapor4Life to ship to me as it does to buy the cartomizers. Anyone have any suggestions and thanks for you help.