Most commonly seen in the auto focus form it was also produced in a manual focus version, this one is a Nikon F (Ai) mount. It is a relatively simple design of 5 elements in 4 groups that natively goes to half life-size (full life-size with a screw-in adapter lens).
I used this excellent lens before scoring a, usually very expensive, Tokina 90mm ATX f2.5.
The first thing you notice when handling it is the incredibly light weight due to nearly every component (though not the mount) being made of moulded toy-grade plastic (you can see the seam line clearly on the barrel for instance on the picture below).
Not really calculated to inspire confidence or pride of ownership; but it works fine and the focusing is nice and firm.
Nice and sharp at the middle apertures; say f5.6-f11 but it's quite ok wide open.
Lenses with relatively few elements often have very nice colour out of the camera and this lens to my eye definitely demonstrates that characteristic.
As I said previously, had I not snagged a Tokina 90mm I would still be very happily using this lens (and indeed it cost me so little that I delayed reselling it).