Those are Sucobox spade to BNC adapters. They are connected to the speaker outputs of the LHC-208 to attenuate the signal so you can plug The 208 into a preamp and use it as a stand-alone DAC. It seems convoluted but it works remarkably well.
The wire is the standard Dart to Zeel Link 50 ohm BNC cable. 50ohm BNC is the preferred interconnect between DarTZeel components.
Same as goldmund speaker cable
I found that many Swiss manufacturers like to use coaxial cable for signal transmission.
But there are few coaxial cables on the market for analog signals!!
Most coaxial cables are for high frequency or digital signals used.
early in my darTZeel days i did try a number of BNC digital cables in comparison with Herve's own cables and my Evolution Acoustic BNC's.
the generic digital and broadcast (BNC cables were much used in pre-digital commercial TV installations) versions all sounded flat and lifeless. that was 15 years ago now. they worked functionally fine......but were not satisfactory for the music. i still have a bag full of these in my attic upstairs.
i even had Audience build a set of BNC's with their high level interconnect cables, but they did not sound very good. that was when i first got the Evolution's which bettered Herve's cables.
so it's not trivial to find a good quality analog music 50 ohm 'zeel' BNC. Evolution used darTZeel electronics for their design work, and is/was the USA darTZeel warranty place too, so it was a natural fit there and they able to make an optimal 'zeel' cable to my ears.
Those used horrible materials. The coax will always remain a compromise because of the need to use the braid as a signal carrying conductor. And because of geometry.
My point was that newer, well regarded digital cables are pretty close to what a really good analogue BNC cable could sound like. There are just too many constraints to develop something dramatically different. Whether the 50ohm termination makes this endeavour worthwhile is another question.
I think van den hul is the first wire manufacturer to introduce coaxial digital wires into analog signal transmission .Their mc-silver it 75 is the standard 75ohm specification ,mc-silver 65g is standard 50ohm specification.But the sound performance in analog used does not seem to be favored by most people?