Dr Pen is the brand used by many schools when teaching microneedling. I am pleased with this nodel. It has a comfortable stainless housing with and feels comfortable in the hand. It has the options to use corded with enclosed 6.5' cord or is rechargeable with the C style USB plug. It comes with a latching storage case. The fine needles are designed for comfort. It comes with 10 needle cartidges that 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. I appreciate the low battery indicator. The depth dial adjusts smoothly even with gloves under a plastic sleeve.Collagen induction therapy is controlled wounding of the skin to stimulate collagen production, reduce fine lines and wrinkles, and reduce scars. Care must be taken when performing this procedure. Done improperly, it can lead to scarring, injury, or infection. Please pay attention to the enclosed pamphlet for proper needles and depth. Watch videos on proper protocol from reputable sources by professionals.