Features: 2.4G Wireless X System: Can be connected with flash triggers seamlessly, has 100 meters large transmission distance, multiple groups, and channels, interference proof and reliable. Compatibility: Specially designed camera photography accessory replacement for Sony A77II, A7RII, A7R, A58, ILCE6000L, etc. Specifications: Guide Number (1/1 output, 200mm): GN60(m ISO100) Flash Duration: 1/300s-1/20000s Flash Coverage: 20-200mm Auto Zoom: (Flash coverage set automatically to match the lens focal length and image size) Manual Zoom: Swinging/ tilting flash head (bounce flash): 0-330° horizontally and -7°-120° vertically Multi Flash: Provided (up to 100 times, 199Hz) Sync Mode: High-speed sync (up to 1/8000s), first-curtain sync, and second-curtain sync Exposure Control System: TTL auto flash and manual flash Wireless Flash Function: Transmitter, receiver, off Transmitter Range (approx.): 100m Controllable Receiver Groups: A, B, C, D, E (E group can be controlled by X series flash trigger) FE Lock: With FEL button or * button Flash Exposure Compensation (FEC): Manual.FEB: ±3 stops in 1/3 stop increments Manual FEC and FEB can be combined) Transmitter Groups: A,B,C,D Channels: 32 (1-32) Modeling Flash: Fired with camera's depth-of-filed preview button Effective Range (approx.): Center: 0.6~10m/ 2.0 ~ 32.8 feet Periphery: 0.6~5m/ 2.0 ~ 16.4feet Full Power Flashes: Approx. 330 times Power Source: NI-MH battery (recommended) or LR6 alkaline battery * 4 (not included) Recycle Time: 0.1-2.6s (rechargeable Ni-MH battery) Power Saving: Power off automatically after approx. 90 seconds of idle operation. ( 60 minutes if set as receiver) Sync Triggering Mode: Hotshoe, 2.5mm sync line Max. Transmitting Power: 5dbm Product Size: 19*7.6*6.4cm/ 7.4*2.9*2.5in Product Weight: 405g/ 14.2oz