PocketWizard introduces the Plus IV Tranceiver with the many professional features we've come to expect plus TTL on-camera flash combined with remote manual flash using most Canon, Nikon, Panasonic cameras and some Fuji and Olympus equipment. The Plus IV has 32 channels (16 standard and 16 Quad Zone). Besides eliminating interference this also allows you to trigger flashes in 4 separate (A,B,C,D) zones when doing multiple setups. Auto-Sensing automatically selects the transmitter or receiver mode appropriate to the setup. Auto-Sensing also works in tandem with Auto-Relay mode to allow to can also trigger a remote camera along with remote flashes. Two-Stage Triggering technology allows to wake and focus your camera by partially depressing the test button and fire it by fully depressing it.