Only used a few times but hardly dry and straighten my hair so surplus to needs. It does work amazingly.

Some info about the Duet:

2-in-1 hair dryer brush, wet to blow dried with no heat damage and 3x more volume. Ideal for all hair types and lengths BLOW DRIES. REINVENTED. – Designed for wet hair, ghd Duet Blowdry harnesses the power of airflow to also heat the barrel and bristles for volume and shine with no frizz. NO HEAT DAMAGE – Sensors monitor the temperature 400x per second to ensure no heat damage whilst blow drying and styling wet hair. 50% MORE SHINE – Heated bristles engineered in a lattice formation for a flawlessly smooth glide, enhance shine by 50% without flyaways. 24HR LONG-LASTING RESULTS – With up to 50% more humidity resistance, ghd Duet Blowdry respects your hair's natural moisture for longer lasting styles. AUTOMATIC SLEEP MODE – After 30 minutes your styler will automatically switch off so you have peace of mind.