AR3 triode

In order, these valves measure 86x35mm, 86x35mm and 84x35mm overall. The first and third examples have the I/S2 and the second has the I/S4 interservice base.

This first example was made by MOV.

Above is the I/S4 interservice base. This valve carries the serial number A951. It was made by MOV.

Above is the I/S2 interservice base. This valve also carries the markings VF2 and LF04 (or IF04). It was made by Ediswan.