BIO:iONIC SMART-X™ Hair Diffuser, New In Box. Experience another element of styling control with the SMART-X™ Diffuser. Only compatible with the SMART-X™ High Efficiency Dryer, the SMART-X™ Diffuser broadens and reduces airflow from the dryer evenly, to gently dry, define, and reduce frizz in naturally textured hair. Evenly spaced, tapered fingers also separate hair to lift and shape its natural texture. The result: Beautifully defined curls and waves with a better-than-dried look.