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.

3M 77512, Cloth Belt 777F, 60 YF-weight, 1 in x 42 in, Film-lok, Single-flex, 7010307736, 200 per case
Dynabrade 95544 Gear Grease, 2.5oz. Tube
3M 87449 Silver Depressed Center Grinding Wheel, T27 Quick Change, 9 in x 1/4 in x 5/8-11 Center Hub Thread, 7010409732, 20 per case
3M 11137, Roloc Disc 361F, 50 YF-weight, TR, 1-1/2 in, Die R150S, 7000045094
3M™ 72016, Remote Alarm & Strobe 529-05-20, Audible, 7000131708, 1 EA/Case
3M 15913, Scotch-Brite Roloc Disc High Strength, TR, 2 in X NH A Medium, 7000000710
3M 53914, Performance Plus Duct Tape 8979N Nuclear Red, 48 mm x 54.8 m 12.1 mil, 7000049014, 24/ case
Dynabrade 51632 .1 hp Straight-Line Pencil Grinder, Central Vacuum, 1/8" Collet
Standard Abrasives 32985, Aluminum Oxide Overlap Disc, 714721, 60 Grit, 2 in x 8-32 x 2 Ply, 7100116380
3M 05579, Cloth Belt 577F, 80 YF-weight, 2 in x 48 in, Film-lok, Single-flex, 7010308379, 50 per case
3M 49936, Roloc Disc 361F, 36 YF-weight, TSM, 2 in, Die RS200PM, 7000119014
Dynabrade 51708 .1 hp Straight-Line Pencil Grinder, 35,000 RPM, 3/32" Collet
3M™ 07012, Supplied Air Hose W-9435-100/07012(AAD), 100 ft, 3/8 in ID, Industrial Interchange Fittings, High Pressure, 7000005375, 1 EA/Case
Dynabrade 51700 .1 hp Straight-Line Pencil Grinder, Rear Exhaust, 60,000 RPM, 1/8" Collet 
