This is a new 24 volt quartz replacement clock for Borg made electric aircraft clocks which were installed as original equipment by various aircraft manufacturers.  This clock will fit in some Cessnas, Pipers and Beechcrafts and others.  The bezel measures 2.375 inches square.  The clock is 1.947 inches deep.  It includes a wiring harness and mounting screws.   
This clock is for use as a time indicator and is not classified as a flight instrument.   We do not certify these clocks.
 
This clock is manufactured by Instrument Services, Inc.