These cables break out from the 26-pin MIL connectors widely used by UK broadcasters and facilities companies, and are wired to the standard (originally BBC) pin convention. These use FSJ-8 individually jacketed multi cable, with numbered cores that correspond to the circuit number. XLR connectors are Neutrik NC3FXX and NC3MXX.
Manufactured by Canford.
Other variations of connectors and lengths are available to special order.