FLASH
Type  Radio transmissions wireless Speedlite transmitter
Compatible Cameras  Type A EOS cameras (E-TTL II/E-TTL autoflash)
Sync Speed  High-Speed Sync provided
Flash Exposure Confirmation  Flash exposure confirmation lamp lights in green*
                          * If it does not light, shooting is not performed with the standard exposure
FE Memory  Yes
Exposure Contol
E-TTL II / E-TTL autoflash  Yes
Manual 1/1 - 1/8192*¹
        ( First curtain only when the second curtain is set.)
        Less than 1/128 power possible only with Speedlite EL-1, used as receiver unit(s),
Multiple  1/4-1/8192*¹
        1-500Hz
       Less than 1/128 power possible only with Speedlite EL-1, used as receiver unit(s)
Wireless Functions
Transmission System  Radio Transmission
Transmission Range  Approx. 98.4 ft. (30m)
Flash Ratio Control  1:8 - 1:1 - 8:1, power 1/2-stop increments
Flash Coverage  Transmission Angle: 360° all around
Second-curtain Sync  Yes*²
                  *² Cameras that support wireless second-curtain sync as of February 2021:
                  • EOS-1D X Mark III*³
                  • EOS R5*³
                  • EOS R6*³
                  • EOS M50 Mark II
                   *³: Camera body must have firmware installed that supports Speedlite EL-1.
Receiver Operation Confirmation Green Light
                            Lit: Radio Transmissions Okay
                            Red Light
                            Lit: Not Connected
                            Blinking: Transmission Error/ Too many units (Sender units + receiver units = more than 15 units)
                            Orange Light
                            Lit: Sub-sender transmission
                            Blinking: Receiving remote release shooting, linked shooting signal
Receiver Unit SE Mode Cancellation The test flash button can be pressed to test if the receiver units fire or cancel the auto power off status.
LCD Panel
LCD 172 x 104 dot display
General
Power Source AA/LRG Alkaline Batteries x2(Ni-MH and Lithium batteries can also be used)
            Battery Life: Approx. 10 hours continuously *When using AA/LR6 alkaline batteries (At a room temperature 73°F/23°C).
SE Mode  Power off after 5 min. of idle operation
Dimensions  2.7 (W) x 2.4 (H) x 3.0 (D) in. / 67.4 (W) x 61.5 (H) x 77.4 (D) mm
Weight  3.9 oz. / 110g (excluding battery)