SIRIM AND DOSH CERTIFICATE Securefit Pressure Diffusion Technology: Flexes and self-adjusts to the size of the wearer's head. Reduces pressure and increases comfort for all day wear. Fits head sizes from 6-1/4 to 8 (50-64 cm) Optimized Comfort: With 2 levels of height adjustment. Contains a premium washable and replaceable sweatband that is made of moisture-wicking material designed to help keep workers cool and dry. 3M Uvicator Sensor: A visual cue when it's time to replace the hard hat due to UV exposure.