The ESX-8GT is an expansion module for the ES-4, ES-40, ES-5 or FHX-8GT, adding 8 on/off outputs for use as gates, triggers, clocks etc. from one expansion header.
Power is supplied by the hosting ES-4/5/40 module, and is used for the LEDs only. I.e. with no LEDs lit, the current draw is 0mA.
Functionally equivalent to the ESX-8GT mk2, the mk3 adds illuminated jack sockets, and matches the look of the ES-8.