The new radio-enabled wireless Speedlite Transmitter ST-E10 inherits most functions of its predecessor , the ST-E3-RT , but is much smaller and approx . 56 % lighter . It has enhanced communication amongst multiple Speedlites , with a transmission distance of up to 30m at any angle . Up to 5 groups or 15 individual flashes can be controlled via one transmitter . It also supports E-TTL II flash , manual flash , strobe and external flash metering . The ST-E10 features a battery-less design and has the same quick access Menu button for instant adjustment . Wireless flash setting is also possible via the Canon Camera Connect app without having to touch the camera or flash .