The OST-4 V2.0 enclosure features Heritage Audio's On Slot technology, providing maximum protection and isolation to every channel. While most 500 series enclosures on the market have a relatively simple power supply, powering channels in parallel, each channel of the OST-4 V2.0 has its own power supply, individually regulated and isolated from the rest. This ensures that each 500 Series module installed will operate to its maximum potential and that no "power-hungry" or even faulty module will compromise the performance of another. In addition to reduced interference, many 500 Series devices exhibit lower self-noise and better performance when racked in the OST-4 V2. especially mic preamps. - On-site technology - Maximum audio rail current: 1.8A per rail (2.0 amps non-continuous), or 400mA per rail per slot, whichever comes first. - Maximum phantom power current: 140mA. - Working voltage: 100-240 VAC.