Another comparison shot of the two units; this time of the back. Stamps can be seen on both units indicating the age of the units (the F-P was made in 1955; the Tabet unit dates to 1959). Also evident is the potentiometer that was used to adjust the sensitivity of the unit. You can also see that both units were made to fit a normal meter socket, but the Tabet does not incorporate the typical sealing arrangement likely because of the location of the sensitivity adjustment. It was also built without the storage hanger that all socket-type meters have.