FLOWN APOLLO 9 ALTIMETER COVER

Command Module altimeter cover, aluminum, 2½ inches in diameter, original velcro square to recto, assembly part number "SEB 33100063-302" serial number "1006." 

SIGNED and INSCRIBED "JIM MCDIVITT FLOWN ON APOLLO 9." With signed provenance letter from McDivitt. The Command Module altimeter was used to indicate pressure altitude of the Command Module up to 60,000 feet. Commonly referred to as a "Light Plug", such covers were developed to allow the astronauts to create a darker environment to better sleep in.