The hulking pistol is a Tektronix A6203 100 A probe, the little black pencil is a Tek A6302 20 A probe:
The absurdity of measuring a 600 mA (peak!) current with a 100 A probe isn’t lost on me, but those things have become genuine eBay collectibles over the last few years.
For low-frequency signals, you could probably get by with a Fluke i410 Hall effect current clamp.
Yo, Eks, babes, remember me in your will … [grin]