If you want to use the obj, you'll have to run the script to uncompress all your Poser files. an obz is the compressed obj file.

I am not on my Poser machine, but I believe you look under Scripts and it should be there.

It will ask you if you want to delete the compressed files after you run it.

If I had a nickle for ever time a woman told me to get lost, I could buy Manhattan.