Untitled 1The ProMaster 170SL Speedlight works with your camera to add light where you want it. It automatically adjusts its exposure and light beam to match your camera and lens settings. The articulating head can be adjusted for a variety of swivel and bounce positions; and is compatible with many light modifiers. The 170SL's powerful guide number of 52m/171ft combined with 180mm zoom head can illuminate subjects from afar. The built-in wireless system provides expanded off-camera lighting options. Wireless manual functionality is non-TTL (F1 and F2 modes)+ Durable tilt / swivel head+ Quick release locking foot+ Durable high voltage battery port+ High quality buttons and switches+ High grade zoom motors and capacitors+ Custom designed 2-lens flash head for best quality of lightThe 170SL is a speedlight that can grow with a photographer. Advanced users can explore features such as:+ Rear Curtain Sync+ RPT (stroboscopic) mode+ Flash exposure bracketing+ Wireless manual functionality (non-TTL)Includes a custom designed case with storage for 4 spare batteries- Guide Number: (ISO 100) 52 m/ 170' at 180mm reflector position - Maximum output power: 400 lx-s at 10' / 3m (at 180mm zoom position)- Flash Coverage: 24-180mm (18mm with wide panel)- Auto/Manual Zoom- Bounce/Swivel Flash Head- Bounce Position (degrees): -7, 0, 45, 60, 75, 90- Swivel Position (degrees): Right 0-180, Left 0-90- Built-in wide panel (18mm) and bounce reflector- Flash Duration: 1/800-1/20,000 second- Color Temperature: 5600K- Exposure Compensation: +/-3 EV- Slave Mode: Optical F1 and F2 modes (non-TTL)- Recycling Time: Alkaline cells 0.2-4.55; NiMH cells 0.15-2.5 seconds- Net Weight: 14 oz/396 g (without batteries)- Dimensions: 7 3/4" x 3 1/16" x 2 5/16" (196.8mm x 77.8mm x 58.7mm)- Power Source: 4 x 1.5V AA alkaline batteries, 4 x 1.2V NiMH batteries, optional HV external power source