The 1194-10-AL-24 from RAF Electronic Hardware is an unthreaded round aluminum spacer with a 3/8" round size, 3/4" length (0.813" / 20.64 mm) and 0.192" ID, in a black finish.
The 3M 1194 8" X 10"-25 from 3M (TC) is a 1194 copper foil Radio Frequency EMI shielding sheet, non-conductive and single sided, measuring 8.000" (203.20 mm) x 10.000" (254.00 mm) x 0.003" (0.07 mm).