The AL-1 series of Annunciator lights from ELECTRONICS INTERNATIONAL are more attractive, operate on less power and are smaller than the old fashioned indicator lights. These lights are an excellent indicator light for displaying boost pump on, gear status, power on, flags, etc. Also, they can be used as remote warning lights for any E.I. instrument featuring an external warning line. They are available in different light colors, operate on a 12 or 24-volt system and have a service life of over 1000 times that of incandescent bulbs. Mount hole: 5/16" . Size: .4" diameter x 1" depth. The come with 32" leads and E.I. documentation and certifications.