Yongnuo 2PCS YN-560IV Manual Flash Speedlite Light + YN560 TX LCD Wireless Flash Trigger Remote Controller For Canon DLSR Cameras+Huihuang USB LED free gift *Supports Wireless Master Function The YN560 IV can be used as master unit, provides 3 independent groups with controlling ability, realizing remote control the flash mode, flash output and focal length of the YN560 IV and YN560 III. *Supports Wireless Slave Function, fully supports YN560-TXRF-603I/IIRF-602 Wireless transmitter *Multiple Trigger Synchronous Mode Supported The YN560 IV can triggered through the set top of the camera, 2.4G wireless triggering, S1 and S2 pre flash cancel mode. *GN58 @ ISO100105mm High Guide Number 2.4G wireless speedlite, supports M/Multi/-- mode. *Sound Prompting System When the sound prompting system is enabled, the different sound ways will prompt different operating state of the flash so as to allow you focus on shooting.