Apollo Optical Unit sextant bellows assembly, approximately 11″ in diameter and 6.75″ in height, made of stainless steel and consisting of a doubled ring wall, with part and manufacturing numbers stamped into lower base ring, "Flexonics 107921, A. C. Spark Plug 1899952, Serial No. 83B5603," and dated "8-26-63." In fine condition. This bellows was used to form a seal between the Apollo Optical Unit Assembly sextant side and the Command Module wall. Isolating the optical unit from structural stress, the bellows' flexibility slowed for slight changes in the Command Module wall as the pressure changed from earth atmospheric to space vacuum. An integral part of the Apollo Optical Unit sextant, which allowed astronauts to update the IMU's settings based on sightings of stars and planets. Please contact RR Auction for a shipping quote.