Inside and outside, a pair of old AVO8 Mk6 multimeters. Little used these days, and no longer the first choice of measuring instrument. Precision made, and hand assembly of some parts, always meant they were expensive. Could be awkward and difficult to repair, although much easier to work on than the Mk3, Mk4, and Mk5 versions that we used to have many of.

Some faults as in the sticking mechanism in the one on the right, were best sent to the experts, and expensive to repair. Not worth it these days, as if the parts and expertise are still available, we could instead buy more than a dozen good quality digital multimeters, that would be more accurate, more robust, smaller, lighter, more capable, more reliable, and easier to read. But there's little hand precision or craft in their machine manufacture, and a battery is required for them to measure voltage and current, unlike the above.

The Lecturing Staff of the day have always reached for the equipment they are most familiar with. Long ago when I started working at the College, it would be for an "AVO". Not so these days. The digital ones do have faults too, not helped by some of the rough handling they receive from the users. At least they're much easier to work on. Second uploaded Blip, of years ago, was part of the circuit board of such a meter.