Upgraded version---- HF-9 whisper is newest upgraded version of model HF-8 and the major change is the noise much lower than previous model. Note: this h2ofloss water floss is much quieter than most brands in market but there still exists noise | 6 pressure settings with “pause” position on handle----Pressure range from 5-110 PSI. Choose your favorite pressure setting and customize your teeth cleaning experience. You will immediately realize flossing becomes easy and enjoyable. | 1200 pulses/minute Frequency----The most comfortable frequency according to survey. The dental flosser comes with overheat protection function, it will automatically stop working when overheated, but can be restarted after 2 hours | Suitable for whole family --- It’s a perfect oral irrigator system for anyone with braces, implants, crowns, or periodontal pockets. Including 12 multifunctional tips-4* jet tips, 2*tongue cleaning tips, 2*orthodontic tips,2*periodontal tips,2*nasal tips | Buy with confidence: H2ofloss provide 24 month warranty to ensure you make decision with ease and confidence. Note: Compatible with 110VAC/60Hz outlets, for use in North America only.