you need a special grip thats sold seperatly with and without click adjustment like the cheyenne -with this you can the stigma carts on every machine use. The pen stigma rotary is the only machine from stigma that use the stigma cart system exclusive. All other work over the grip that you can use or a fki cart grip. The soldier is my favorit because the brushless motor and the stroke is over a magnetic cam to change in secounds. The carts are nice ,very good needles ,perfect ink flow and its very nice to to be able to rotate the cart and not the machine -so mach improvmentis possible in the way to tattoo and no one bad cart in the box. But i have a fki grip to when some stigmas are out .