These handy computers measure 8" in diameter and were ubiquitous in WWII aircraft that included a navigator crew member, such as the B-17 Flying Fortress and B-24 Liberator. Offered here are new old stock units packaged for long-term storage post WWII. Although they have been stockpiled in a non-climate controlled hanger for close to 65 years, and the packaging reflects this, the contents are pristine.