Full and Low range options tor accurate readings, sterilizable for ultimate hygiene. The built-in handle helps patients use the Personal Best correctly. And when not in use, the handle converts into a carrying case for ultimate portability and protection. Safety Mouthpiece for extra hygiene reduces the risk of cross-contamination during multi-patient screening, and the one-way valve prevents patients from inadvertently breathing in air through their meters during peak expiratory flow rate testing. This integrated system helps patient comply with treatment regimens. The color-coded indicators can be adjusted to delineate a patient's green, yellow, and red zones based on personal best peak flow.