The magnetic mechanism that draws in Steve, Betty and Barry is a redress of the teleportation device from the earlier episode "Panic".
This is Production number 4722. It was the 22nd episode of the second season to be produced, but the 20th to be broadcast.
Dr. Zoral refers to a previous story about an oversized robot (The Mechanical Man (1969)). In that one, Zoral was played by Stuart Margolin, who is most famous for playing Angel, the always-in-trouble con-man in The Rockford Files.