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.

Standard Abrasives 717639, Aluminum Oxide Straight Cartridge Roll, 5/8 in x 2 in x 3/16 in 50, 7100115215
Dynabrade 96101 Dynabrade Air Lube 10W/NR 24 Per Box
3M 32306, 641WY, 3" X 30", 600 Mesh, Diamond Cloth Belts, 7010534829
Dynabrade 53270 7" (180 mm) Dia. Right-Angle Disc Sander
3M 76679, Cloth Belt 777F, 60 YF-weight, 6 in x 48 in, Film-lok, Single-flex, 7000118459, 20 per case
3M™ 17379, Versaflo™ Length Adjusting Breathing Tube BT-30, 7100009685, 1 EA/Case 
