Phi Universal Microneedling Cartridge 12P - 20pcsEach box contains 20 Universal Microneedling Cartridges, compatible with all universal tattoo, permanent makeup and MTS machines. Microneedling cartridges are designed to create micro channels that penetrate deeper into the dermis (the middle layer of skin), to promote and significantly improve product absorption. This technique stimulates the production of collagen and elastin, boosting and kickstarting your skins natural regenerative healing