This oblong 501 adapter holds an oblong filter over your (expensive) organic vapor cartridge to protect it from becoming clogged with particles when working in dusty environments.
The adapter fits over a 3M™ oblong filter, and then snaps onto a 3M vapor cartridge.
Sold by the each.
All 3M facepiece respirators can be used with ANY of 3M's vapor cartridge and pre-filter combinations —
• Vapor cartridges attach directly to the bayonet fitting on the mask
• White oblong filters are attach on top of the oblong cartridges by using a #501 adapter, which snaps onto the cartridge
• All round filters can be attached to a cartridge by using #502 bayonet adapter, which snaps onto the cartridge
• All round filters can also attach directly to a facepiece, without a cartridge, when vapor protection is NOT required, and only particulate protection is required