Features the punch card system for automated dialing.
As Five-O prepares to close in Colby's operation near the end of the show, the shipment of cassette recorders arrives by air and is then transported in an Asiam Air Cargo truck, which is the same company as in the season four show "Air Cargo -Dial For Murder".
When Chin is hijacked carrying a load of Tranasonic recorders, the bad guys are waiting in a Ford Econoline van, License number 68-452. This very same van would be the one Dina is seen driving in "A Woman's Work is With a Gun".