This is the surplus Gen III image intensifier tube (an MX-10160 Gen III intensifier tube used in the helmet-mounted AN/AVS-6 “ANVIS” aviation night vision imaging system, which we purchased on eBay®) that we used to build our setup to image interference patterns from our single-photon two-slit setup (book‘s Figure 93). The tube is supplied by 3VDC from two AA cells. We used the same camera to record interference patterns from a single-photon Mach-Zehnder interferometry setup (book‘s Figure 132).