Here is a silver plated pocket cup ( also called folding cup, travel cup or collapsible cup even “collapsion” cup in some ads and catalogs).
The bottom of the cup is marked “Pairpoint Mf’g. Co. Quadruple Plate 426” along with the Pairpoint trademark of a “P” in a diamond shape. The cup measures approximately 2 and 1/2 inches in diameter at the top and about 1 and 7/8 inches at the bottom. Fully extended it is approximately 2 and 3/4 inches tall; collapsed it is slightly over an inch.
The exterior of the cup has a decorative machined design finish…different on each of the three sections. Not only is this attractive but also provides a rough surface for a good grip.
The cup comes with its black japanned tin carrying case. On the top is written “Pocket Drinking Cup The Pairpoint Mfg. New Bedford Mass”. The case measures about 2 and 3/4 inches in diameter and about 1 and 1/4 inches high.
It would make a nice traveling julep cup!
It’s available for sale here at my Etsy shop: https://www.etsy.com/listing/579082752/pairpoint-mfg-co-silver-plated-pocket