The ProMaster 200ST-R Speedlight works with your camera to provide powerful light, TTL exposure, and a wide range of advanced features including HSS high-speed sync, second curtain sync, and more. The articulating head can be adjusted for a variety of swivel and bounce positions; and is compatible with many light modifiers. The 200ST-R's powerful guide number of 60m/200ft combined with 200mm zoom head can illuminate subjects from afar. The built-in wireless 2.4 GHz radio TTL system provides expanded off-camera lighting options when commanded by a ProMaster SM1S Speedlight Master Transmitter. Wireless non-TTL (F1 and F2 modes) optical slave is also on-board. + Guide Number: (ISO 100) 60 m / 200' at 200 mm zoom head position + Flash Coverage: 24 - 200 mm (18 mm with built-in wide panel) Auto/Manual Zoom + Bounce / Swivel Flash Head Bounce Positions: -7º, 0º, 45º, 60º, 75º, 90º Swivel Positions: Right 0º, 30º, 60º, 90º, 120º, 150º, 180º ; Left 0º, 30º, 60º, 90º + Manual Output Power Range: 1 - 1/128 + Flash Duration: 1/800 - 1/20,000 second + Color Temperature: 5600K + Exposure Compensation: +/- 3 EV in 1/3 EV increments + Wireless Slave Mode: 2.4 GHz radio, 15 channels + auto, 3 groups A/B/C (up to 15 units in a group) + Wireless Range: 325' / 100 m + Recycling Time: Alkaline cells 0.27 - 5.2 s ; NiMH cells 0.15 - 3 seconds + Net Weight: 15 oz / 425 g (without batteries) + Dimensions: 7 ¾" 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 supply + Maximum output power: 500 lx-s at 10' / 3m (at 200mm zoom position) + ProMaster 3717 USB firmware downloading cable for computer connection