Shimano UG cassette 6 speed 13-28 NOS

Shimano UG Uniglide first generation cassette. This fits 6 speed compatible shimano UG free hub bodies that feature evenly spaced splines. Not compatible with modern HG splined freehub bodies with a narrow then wide spline. 6 cogs for Shimano 6 speed index systems. 13-28 cog range. 
Last outermost cog is threaded to fit on UG freehub bodies.

 
Condition: There is surface rust, some water marks, and possible soot from a literal fire sale. Recovered from a burned down bike shop in Oregon. No box. There is no indication that this cassette was mounted on a wheel or a chain touched it. So it’s old stock, out of box condition.
Prepaid shipping CONUS.