Two types of alarms – one audible and one visual – alert user to either a low battery or low flow, such a when a particle filter is fully loaded. LED lights on the battery indicate its charge status on and off the charger.
The 3M Versaflo TR-307N+ PAPR assembly includes a TR-302N+ PAPR unit, TR-371+ filter cover, TR-327 easy clean belt, TR-332 battery, TR-341N battery charger kit, TR-3712N HE filter and a TR-3600 Pre-Filter.

Dynabrade 11684 Dynabelter Contact Arm Assembly 4" DIA X 5/8" W., 40 Duro Serrated
ACS Diamond Cloth Belt, CX1250 1" X 72" 125U
3M 20910, PSA Cloth Disc 348D, 60 X-weight, 2 in x NH, Die 200P, 7000118872
3M 94717, Cubitron ll Cloth Belt 947A, 80+ X-weight, 1 in x 30 in, Fabri-lok, Single-flex, 7010294445, 200 per case
Standard Abrasives 722809, PSA A/O Extra Disc, 5 in x NH, 60, 7010368721
ACS CX1250 Diamond Belt, 1/2" X 24" 30u
3M 26136, PPS Series 2.0 Adapter, Type S32, 18 mm Female, 1.5 mm
Thread, 7100135952
3M 37001, Combination Dual Airline Back-Mounted Breathing Tube SA-2600/37001(AAD), 7000002044, 1 EA/Case 
