For the best user experience with Nuto Cartridges, it is recommended to use the New Nuto Pen. The new Nuto Pen has fixed some issues that existed in our previous Magnetic Pen versions of Enzo, Rogue, and Radical. The Nuto Tattoo Pen is designed to work with Nuto Cartridge Needles. This pen uses a high-performance 10,000RPM motor. This pen has a 1" Inch grip handle and needle protrusion is fully adjustable. What are Nuto® Magnetic cartridge needles? Most cartridges use a membrane, spring, or rubber band to retract needles back to initial position . When your machine pushes the needle out there is back force being put on your machine causing stress and wear on your machine. This is why some cartridges require stronger motors at a higher voltages to work. With Nuto Cartridges, there is no added stress to your machine. The top of the cartridge connects to the machine via a heavy duty magnet, essentially creating a standard loop bar. The needle then follows the motor in and out of the skin at the same rate as a standard on bar needle while keeping the benefits of the safety cartridge. With this zero-resistance design your machine will last longer and work easier at lower voltages. Included: Tattoo Pen and Machine cords. Pen Weight: 5 oz Warranty: 3 Months Needle Swing: Adjust your needle swing length with a simple twist of the grip.