• Adjustable needle head that gives you flexibility to switch to different needle depths. • Replacement needle head is used with the ORA Electric Microneedle Roller Derma Pen System • Comes with 3 replacement needle heads. When should you dispose of the roller? The roller should last more than 15 treatments with proper handling. But if you accidentally drop the roller and bend the needles, it is highly advisable to dispose of it immediately. You might need to replace your roller every 2-3 months, as the roller can become dull quickly when penetrating the skin. For health reasons, do not share a roller. How often can I use the roller? For beginners, rolling every other day can be done with 0.25mm or 0.3mm needle length only but it is advised to wait a few days for your skin to heal before another treatment. For 0.5mm roller, you can use it once per week. For the 0.75mm, you can use it once per month and gradually increase to once per week.