The pack is daylight loadable, it has a protective sleeve you pull out once it's in the adapter, similar to Polaroid/Fuji pack films if you're familiar with those.
From Mopar_guy's info it sounds like you do have a 4x5 pack. But as John said, you need a film pack adapter. The sheets inside the pack are slightly larger than standard 4x5 sheets, and they are thinner, the same thickness as roll film. If you were determined, you could probably remove the film and with some trimming put the sheets into standard holders, though flatness would probably be a problem.
If you put it up for sale, you'd probably get buyers, how old is it?