Do I have a posi or locker??

[thelonerife]

I have a 3/4 ton 10 bolt rear. I would like to know if it is a posi or locker. I took the cover off and it doesn't look like other posi's I've seen on 1/2 tons or cars. Looks like it has smaller spider gears next to the ring gear. When I have both wheels off the ground and turn one the other goes th same direction. Also when I lost traction in wet grass it left two tire tracks. I would post pics but haven't figured that out yet.I was told by po that it was a 4:10. Any help would be greatly appreciated!!Chuck..