A vintage United States military maintenance supply item, specifically a 4-ounce can of O-147 OAI instrument lubricating oil. The rectangular metal container is finished in traditional military olive drab paint and features a white plastic applicator spout at the top. The front of the can displays yellow stenciled text identifying the contents as lubricating oil for instruments, meeting military specification MIL-L-6085A, AM.2. Identification markings include the National Stock Number 9150-257-5449, the manufacturer R. M. Hollingshead Corp., and a production date of May 1966. Additional markings indicate Batch 38858, contract number DSA-600-11489, and Lehigh Chem. Co. WCLTR-59-5. The reverse side features a stenciled caution statement regarding the oil's interaction with paint, natural rubber, and neoprene. This type of synthetic oil was primarily utilized for aircraft instruments and low-torque electronic components during the Vietnam War period. Volume: 4 OZ. NET.