I may be partial to the Dr Pen devices since I learned microneedling on one. I have several and I like different things about each one. This one is moved to the top of the list. It has a comfortable stainless housing with a good hand feel. It may be used corded with enclosed 6.5' cord or is rechargeable with the C style USB plug. It comes in a latching plastic case. It includes 10 cartridges, two of each size: 12 pin, 36 pin, 42 pin, and nano needles in stainless and silicone. I appreciate that the advanced cartridges are the same as the A9. The fine needles are designed for comfort. The cartridges are locking and have a valve to prevent back flow. It has six speeds and the smooth motor will go up to 20,000 RPM. It has a low battery warning indicator. The depth dial adjusts smoothly even with gloves under a plastic sleeve. All of that being said, while microneedling is not regulated in many states, proper protocol and sanitation must be followed. Collagen induction therapy is controlled wounding of the skin to stimulate collagen production, reduce fine lines and wrinkles, and reduce scars. Done improperly, it can lead to scarring, injury, or infection. Please pay attention I the enclosed pamphlet for proper needles and depth. Watch videos on proper protocol from reputable sources by professionals.