Impossible for me to tell from here.

Kinds of sketchy that the owner does not know or care to list the manufacturer ... could be Trek, Specialized, Giant, or Wal-Mart.

Looks like a Marzocchi Bomber fork, which should be an excellent fork, but the fork could be 20 years old and on its last legs.

Based on the fact that the bike has cantilever brakes (or maybe, upon inspection, V-brakes) I would say that it is probably late-‘80s or early ‘90s, and from the tube size I’d guess a steel frame.

Depending on the age and condition of the fork, I’d trust it for an around-town cruiser and maybe some light trail work .... It looks like it has been well maintained, or maybe the seller was smart enough to clean it really well before photographing it.

There should be a serial number on the bike which mi8ght identify it ... but whatever, the price seems steep for what looks to me to be a 20-year-old bike.

What do you plan to use it for? Serious MTB trails? Commuter? Go-anywhere fun ride? Should work for most easy stuff. A Lot depends on the age of the fork and the general condition of the bike, which won’t show from photos. Might be a great deal if the fork is new of if the owner has recently serviced it.

I strongly suggest posting this in the MTB forum.