This one-of-a-kind digital clock was originally a Computer Measurements Company model 614A Universal Preset Counter. It was built in late 1965, upgraded from a 5-digit to a 6-digit display in 1970, and converted to a clock by me in 2002. It uses vintage Nixie tubes, a form of numeric display that has been considered obsolete since 7-segment LED displays became available in the early 70's. However, many people still prefer the aesthetics of Nixies over more modern display technologies, due to their warm neon glow and individually-formed digits. The exterior appearance of the counter is unchanged - including all the control labels, so it isn't immediately obvious that it is now a clock.
The clock measures about 17" wide, 13.5" deep, and 3.5" high. The case was intended to be rack-mountable, however I do not have the rack mounting brackets for it. It weighs about 19 pounds. The Nixie digits are 5/8" tall: none of the pictures here really do them justice, they are much smoother, and a brighter orange color, than my old video camera is capable of capturing.
The clock's features include: