This is a pure guess, but they might be Inakustik's approximation to a bare wire connection--i.e. if the hole in the binding post was big enough, just thread it through and tighten down. Otherwise, that copper casing of the wires I suppose makes it easier to fit them into your bananas or spades of choice.
https://www.worldwidewholesales.com/ distributes Inakustik in the US; they might know for sure.