JPX 6 Inert Cartridge 4-Pack

Glad there is a inert cartridge to you can practice with. I feel for the cost of cartridge for practice test fires are a little high. But I feel that would be more on the manufacture side not seller side. For the high price of the inert cartridge I would feel better spending that high cost if the dye would stay on someones skin for 48 hours or so. Then I might have a dual purpose use. Practice shoots and to just mark someone for police to find later. But I admit i would want to stop that person not just paint the skin blue with dye. Just looking for way to more justify the cost in my mind. On seller website I would like it to be clearer that pack of 4 is actually 4 canisters contained in 1 cartridge that you slide on and off the gun to for reloading.