This speedlight from Yongnuo puts all the control and power you need right in front of you with a built-in wireless trigger system, allowing you to use it as both a flash unit and as a flash control transmitter for additional flash or strobe units. This functionality makes it a great addition to your gear lineup, whether you're a beginner who wants to explore the world of off-camera flash photography or a seasoned pro who needs the versatility and control that this speedlight can offer. A push-button control interface makes it easy to operate the unit by feel, with fully-manual zoom and exposure control as well as the ability to set custom functions that save automatically for your next session. The base of the flash allows for -7 to +90-degree bounce angles and a 270-degree swivel range, and for all the full-frame flash you need at wide angles, you'll have 18-105mm coverage. For connectivity, you can utilize a built-in PC Sync port or the standard hot-shoe mount, and optical triggering is supported up to 80 feet away indoors or 50 feet outdoors. This flash has an approximate recycle time of 3 seconds at full power and runs on four AA batteries (or an optional battery pack). Features: Less Than brGreater Than TX Master Flash mode: When you set up YN-560IV in TX mode, it can be used as a flash control transmitter. It can trigger YN-560 IV ( RX mode )and YN-560 III ( RX mode ) and also can be used with RF-602, RF-603 II, RF-605 together. Less Thanb