> :

> shawn I have the 3M 5000 mask (i think) $25 @ west marine and it came with
> the thin pre-filters. any idea how you attach them to the mask. there is a
> diagram on the bag that says there is a lever to open the cartrages, but
> my mask doesn't have a lever. Do you tape these pieces to the out side? Am
> I worring too much about it?

There should be a plastic cover on the cartridge. This cover comes off (probably the lever in the diagram) The prefilter goes on the cartridge and them the cover goes on to hold it in place. The prefilters stop the dust particles from clogging the cartridge before the charcoal has been used up.

Ian