Kern Switar 75mm f/1:2.4 camera lens intended for use with the Maurer DAC (Data Acquisition Camera), evidently modified by NASA for use in a particular experiment. The lens measures 3.5" long and 1.75" in diameter, and is hand-annotated with NASA part numbers near the mount: "SEB 33100019-302." This lens has the standard 16mm Data AcquisitionCamera (DAC) lens mount. Both the focus and aperture rings do turn, but have been disabled.
Designed and manufactured by J. A. Maurer of Long Island, New York, the Maurer Data Acquisition Camera was used to obtain sequential photographic data during the manned flights of Project Apollo and Skylab. This type of lens is described in the "Handbook of Pilot Operational Equipment for Manned Space Flight, Report No. CD42-A/SL-997," published by NASA in June 1973: "75 mm. Lens (SEB33100019): This moderate telephoto lens is used primarily for photographing distant objects. With the focal length and narrow field-of-view of this lens, bracket mounting and precise aiming are recommended." It lists the "-302" suffix as a "significant configuration," describing its purpose as "Apollo and Skylab CM unit; standard usage." This variant would typically have the right-angle mirror mount and focus and aperture tabs, all of which are absent on this example. The optics do not appear to have been modified.