BBC Goerz Metrawatt, test leads of that era.
They were made as custom work by Hirschmann Germany.
When KS21 test leads, these were damaged? and or longer wires was required, next close replacement this was Hirschmann measuring cable series.
These have molded banana plugs in both ways, these are secure to handle up to 1000V.
Actual wire diameter isolation 4mm
Inner copper (2,5 mm²) / 32 A
For such analog multimeter, Metrawatt considers as essential wires diameter to be large.
This improves multimeter accuracy, especially when the multimeter measuring current, from uA up to 25A range.
Note: Modern test leads, they support up to 10A as Max, and they are compatible up to a point.
But all analog multimeter characterized as Low impedance, they need higher diameter of test lead wires.