Vitalograph 20980 Mini SafeTway One-way Valve Mouthpieces. For use with peak flow meters and spirometers.

• One-way valve prevents accidental inhalation 
• Completely disposable 
• A low cost alternative to BVF for expiratory testing 
• The low cost, low resistance SafeTway® mouthpiece allows entry of expired air into the measuring system, but not back to the test subject. This simple, yet effective patented design prevents concerns of accidental inhalation of pathogens.
• The SafeTway is an inexpensive alternative to the bacterial viral filter for expiratory only testing. It fits most pulmonary function test equipment, including peak flow meters. An adaptor may be required.