This is an antique pocket-sized compensated barometer made by asprey of london. Besides the barometer function it has a thermometer and an altitude adjustment that calculates up to 8000 feet. This dates from the early 20th century and was a gift to my father in the late 1920s when he was a boy. It has been sitting in a drawer in a dry climate for the last 62 years. The brass case is covered in real alligator skin which is intact but shows some wear. The glass face is clear with no scratches. It works occasionally but the needle seems to stick most of the time.