All V-Series Supplied Air Valves require a supplied air hose to complete the NIOSH-approved respirator system. These hoses are available in many different lengths and are sold separately.
3M 37019, Versaflo Air Regulating Valve Assembly V-300/37019(AAD), 7100077491, 1 EA/Case
$224.35
Factory Stock, 7-10 Day Leadtime, Priced Per Case
Allows the worker to set the airflow to the most comfortable level. Includes the valve and waist belt. It is strictly a regulator and will not warm or cool supplied air to the worker.

3M 29611, 641WY 1/4" X 24", 100 Mesh Diamond Cloth Belt, 7010534832
3M 60339, Nose Cup Valve Assembly 7882, Replacement Part, 7000125976, 20 EA/Case 
