PocketWizard ST4 Power Receiver for Elinchrom RX Flash Units (Black) Uses All PocketWizard Channels: The PowerST4 can be programmed as needed with up to 20 ControlTL channels for Manual Power Control, or 32 standard channels for simple triggering.^Programmable and Upgradeable: Use the PocketWizard Utility with the PowerST4s USB port to program the receiver to any PocketWizard channel and zone.^Manual Power Control: When the PowerST4 is paired with either the MiniTT1 or FlexTT5 on camera^Use the AC3 ZoneController to control up to three zones of light with as many lights in each zone as you want. Use the A-B-C zone switch on the PowerST4 to assign the zone.^HyperSync: HyperSync allows achieving faster X-sync speeds, as fast as 1/8000 second, with full power flash to better freeze action and use wide apertures in bright ambient-light conditions.