Profoto's Air Remote TTL transmitter for Sony is the key to wireless triggering and TTL remote control of its B1 and B2 AirTTL Off Camera Flash heads. Operating on the 2.4 GHz bandwidth, the transmitter, really a controller, has 8 frequency channels and with 3 groups per channel and a range of up to 330' for TTL triggering and 1,000' for normal triggering. Each channel has power ratio capability of +/- 2 stops. If you prefer to use manual you have +/- 9 stops power variation. You've also got modeling light and unit shut-down. The TTL-S, the B1 500 AirTTL and B2 Off Camera Flashes have micro-USB connectors for firmware updates directly from Profoto's website, such as High Speed sync which allows sync speeds as short as 1/8,000 sec. Besides the B1 and B2, the Air Remote TTL-S will also manually remote trigger all Profoto Air packs and monolights but without the TTL feature.