The 7450 V2 series face mask is a reusable, multi-patient, multi-use mask for use with two-way non-rebreathing valves or other mask adapters for connection with flow measuring instruments used in lung function testing procedures with spontaneous breathing adults (>30 kg). The masks, valves, adapters and headgear are supplied clean, non-sterile for pulmonary function testing, exercise testing and respiratory research applications in hospitals and other clinical settings.