Godox CT-16 Wireless 433MHz Speedlight / Studio Flash Remote Trigger has 433MHz transmit frequency. It can secures fast response and stable transmission. Extra umbrella access hole on receiver. It can also wirelessly trigger several kinds of studio flashes via sync cable. Maximum synchronous speed up to 1/250 second. Universal hot shoe interface wireless radio flash trigger. ( don't support Auto TTL functions ) 433MHz transmit frequency secures fast response and stable transmission 16 channels, transmitting distance up to 30m, no limits with directions or angles Maximum synchronous speed up to 1/250 second Compatible with: For Canon 600EX, 580EX II, 580EX, 550EX, 540EZ, 520EZ, 430EX/EXII, 430EZ, 420EX, 420EZ, 380EX For Nikon SB-900, SB-800, SB-600, SB-28, SB-27, SB-26, SB-25, SB-24 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 Other flash models with a trigger voltage of 12V or lower with standard hot shoe Standard 3.5mm Sync jack cable to connect receiver to studio flash Specifications Model: CT-16 Channel: 16 Channels Transmit Frequency: 433MHz Transmitter Power: 12V 23A lithium battery (Not Included) Receiver Power: 2 x 1.5V AAA Battery (Not Included) Synchronous speed: Max. 1/250sec max Outdoor operation distance: max. 30m / 90feet (Open area, No fraise) Indoor operation distance: max. 25m / 75feet Transmitter Dimension: 60x42x30mm Receiver Dimension: 90x50x32mm