Kiierr Laser Cap Hair Growth System 148 Kiierr laser caps, powered by our exclusive PureLaser™ technology, utilize only high quality medical grade laser diodes (no LEDs) to deliver precise, effective LLLT at 650 nm for optimal hair regrowth. With options of 148, 272, or 302 diodes, and total power outputs of 740 mW, 1,360 mW, and 1,510 mW respectively, Kiierr caps offer targeted stimulation for fuller hair. Simply use the 148 and 272 models for 30 minutes every other day, or the 302 model for 6 minutes daily, and start seeing results in as little as 6–8 weeks, with significant improvements typically visible within 4 to 7 months.