Not all laser caps are created equal, and the Capillus brand laser caps are set apart due to its roots in the science of Low‑Level Laser Therapy (LLLT), which is optimized for scalp use. The lasers in Capillus caps emit red light at roughly 650 nm, which is a wavelength shown to be effective in stimulating hair follicles. This wavelength safely penetrates a few millimeters into the scalp so the energy reaches the hair-follicle base without damaging surrounding skin or tissue.