The 12 point tip cartridges are for deeper Collagen Induction treatments and topical anesthetic can be applied to the skin. State regulations vary so please check with your state and make sure you are able to provide this depth of treatment. The 12 pin tip is perfectly spaced for the micro channels and the depth of the treatment can vary using this tip. The 12 point needle is great for texture, scars, skin laxity, fine lines and wrinkles. For lighter treatments the Nano needle is great to use also and is great for sensitive skin types. The Nano needle is used for a light exfoliation and serums will penetrate easier.