Profoto's Air Remote TTL-C for Canon is the key to wireless triggering and TTL remote control of its B1 and B2 OCF AirTTL Off Camera Flash heads as well as D2 heads and the Pro-10 2400 AirTTL pack. Operating on the 2.4 GHz bandwidth, the remote, 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, unit shut-down and first or rear curtain control. The AirTTL flash units have micro-USB connectors for firmware updates directly from Profoto's website, such as High Speed sync which allows sync speeds as short as 1/8000 sec. Besides the AirTTL flashes, the TTL-C will also manually remote trigger all Profoto Air packs and monolights but without the TTL feature.