Specifications: Brand: Andoer Material: Metal + Plastic Color: Black Suitability: -For Nikon SB-900, SB-800, SB-600, SB-28, SB-27, SB-26, SB-25, SB-24; -For Canon 580EX II, 580EX, 550EX, 540EZ, 520EZ, 430EX/EXII, 430EZ, 420EX, 420EZ, 380EX; -For Pentax AF-540 FGZ, AF-360 FGZ, AF-400 FT, AF-240 FT; -For Olympus FL-50, FL36; -For Sigma EF-500 DG Super, EF-500 DG ST, EF-430; -For Sunpak Auto 2000DZ, 622 Pro, 433AF, 433D, 383, 355AFm 344D, 333D Power of transmitter: 23A 12V mini battery(included) Power of the receiver(AC): 2 * 1.5V AAA Alkaline Battery(not included) Outdoor working distance: max. 30m / 90feet (open area, no fraise) Indoor operating distance: max. 25m / 75feet Channel: 16 channels Frequency: 433Mhz Sync. Speed: Max.1/250s Package Size: 10 * 10 * 4cm / 3.9 * 3.9 * 1.6in Package Weight: 148g / 5.2oz Package List: 1 * 4-Channel Transmitter 3 * 4-Channel Receiver 1 * PC Sync Cord(2.5mm to PC) Note: This trigger set do not support TTL function. This item only includes the trigger set and sync cord.