Specifications: Type: On-Camera Speedlite Transmitter Exposure Control Syestem: E-TTL II/E-TTL Autoflash, Manual Flash, Stoboscopic Flash, Gr Flash Frequency: 2405-2475MHZ Modulation System: Primary Modulation: OQPSK, Secondary Modulation: DS-SS Channel: Auto, Ch. 1-15 Wireless Radio ID: 0000-9999 Slave Unit Control: Up to 5 Groups(A/B/C/D/E), Up to 15 Units Transmission Distance: Approx. 100m Flash Ratio Control: 1:8-1:1-8:1, 1/2-Stop Increments Flash Exposure FEB: ±3 Stops in 1/3-Increments(When used with flash exposure compensation) Manual Flash: 1/1-1/128 Power(1/3-stop increments) Stroboscopic Flash: Provided(1-500Hz) Flash Exposure Confirmation: Flash Exposure Confirmation Lamp Lights Model Flash: Fired with Camera' Depth-of-field preview button. Linked Shooting: Provided Custom Functions: 9 AF Assist Beam Emitter: Provided Firmware Update: Provided Power Source: 2 AA/LR6 Alkaline Batteries Ni-MH Batteries(Not Included) Wireless Flash Shooting: Approx. Time: 10 Continuous Hours Power Saving: Power off After 5 min, of idle Operation Package Size: 11 * 9 * 7.5cm / 4.3 * 3.5 * 3.0in Package Weight: 240g / 8.5oz Packing List: 1 * Speedlite Transmitter 2 * Shutter Cable(LS-Micro/C1 & LS-Micro/C3) 1 * Storage Bag 1 * User Manual(English & Chinese)