... but I always prefer the test gear. The HP 202D on top is unusual. I didn't know there was such a thing. The HP 651B beneath it is a classic vintage solid-state wide-range R-C oscillator. And the rack-mount HP 400C is quite unusual. Aside from the odd green color paint, it has a tag that states that it is a "Voltmeter, Electronic, ME-30U, Gillifan Bros, Inc."