Although the F1 lacks the ease-of-use of a digital beacon (i.e., it does not have distance or direction indicators), it has a long range, simple controls, and a small size. If you are willing to learn how (or already know how) to use an analog beacon, the F1 is a solid avalanche transceiver. This was my favorite beacon for many years. See the review of the M2 for general information on Ortovox analog transceivers.
The Ortovox F1 was an extremely popular, single-antenna, pure-analog beacon. The first F1, released in 1989, was light blue and had no lights. In 1990 one light was added and in 1994 the beacon was renamed the F1 Focus and three lights were added (red, yellow, and green). In 2002 the beacon was equipped with larger lights and the case was changed to a darker blue. It was discontinued in 2012.
Newer digital transceivers will occasionally report multiple transmitters (i.e., a "multiple burial") when receiving a signal from a single F1. This seems to be most common with the Tracker2 and the Pieps DSPs when receiving a signal from an older F1.