This Gorham stoplight jigger is 2 1/2"tall with a diameter at the top of 2 1/4" and at bottom of 1 3/4". It weighs 51 grams.
This jigger has a rolled lip at top and two other raised bands. Between each, there is a red, yellow and green enamel stoplight, hence the jigger's name.
On the bottom, it is stamped Gorham sterling 354. Below that are the pour measurements 3 1/2, 21/2 and 1.