This RetinAl-MD technology is made smarter w/ calcium + microspheres so that even sensitive skin won't have a bad reaction. It's FASTER & 20x stronger than Retinol. This redesigned AMP roller head is waterproof, it travels better, the design fits better in your hand, & the needles are laser cut. THIS is the science of anti-aging & the reason we’re #1. It’s as close as close to prescription you can get, & we are constantly knocking it out of the park!