Exclusive to BlanX, O3X is a new advanced formula for professional whitening results. O3X releases oxygen power which removes stains for an intense white smile. These extra fine strips are flexible and transparent for perfect contact with the teeth. The shades of white which can be achieved refer to Vita Classical A1-D4, a well established scale used to determine the colour of teeth by dentists. The innovative, peroxide-free formula is non-abrasive and delicate on gums and enamel.