The Strato ll Multi 5-in-1 Wireless Trigger System gives photographers incredible control over their cameras, speedlight flash unti, and studio lighting equipment. Four channels and four groups provide unparalleled control in the studio or on location. The Strato ll can also be used as a wireless or wired shutter release for your camera. The 2.4 GHz transmitter and receivers offer ranges of more than 400ft with sync speeds of up to 1/250th of a second. Transmitters feature an innovative TTL pass-through hot shoe allowing full TTL mode to be used with dedicated camera mounted flash units. Receivers offer a unique flash wake-up function that reduces battery usage. The trigger sets come with all dedicated cables and receivers and are compatible with Strato 4 in 1 transmitters. The triggers set includes a hot shoe TTL transmitter and a non TTL receiver.