Sonceboz 6500 R.034 Stepper Motor 0.5A/PH 8902.  I have a handful of these and they all have a different gear on the end and some of them have a short pigtail so you may have to splice them.  See photos. 

I purchased this from a university. 

Tag: C-R4358 

Bin: 19H-Cinn

Shelf: .8