Junk item, does not emit light. There's a reason why it's very clean. Used only once. Became unresponsive after emitting light dozens of times. I bought it on AliExpress, and contacting them for warranty return was a hassle, so I just kept it stored. High-energy storage lithium battery: 7.3V 3200mA, total light output approximately 700 times, recycle time approximately 1.5 seconds (1/1 output), low self-discharge rate, less than 1% per month, high and low temperature adaptability. With high-brightness LED light: 4W full white LED light, independent switch control, independent circuit design, so it does not affect strobe return. Multi-mode flash: ETTL/M/MULT, strobe exposure compensation: Flash compensation can be adjusted within a range of +3.0EV, built-in AF focus assist lamp: dot matrix type auxiliary focus, faster. 2.4GHz wireless transmission: 360-degree signal transmission over 50m, supports optical transmission, slave control, S1 and S2 control, 20mm to 200mm free zoom, supports front curtain sync and rear curtain sync. Strobe exposure compensation: Used when the flash is too strong or too weak. Built-in AF focus assist lamp: Used when shooting in dark or low-contrast situations. Specifications: Guide number: 60 (ISO100, 200mm) Coverage range: 20mm to 200mm Flash mode: E-TTL/M/MULT Strobe flash: 1-500Hz System mode: FSK 2.4GHz wireless system, optical transmission, slave control, S1 and S2 control Sync: High-speed sync, front curtain sync, rear curtain sync Rotation angle: Vertical -7 to 90 degrees, horizontal 0 to 180 degrees Manual flash: 1/128-1/1 output (1/3 step) Recycle time: Approximately 1.5 seconds (1/1 output) Display: High-resolution dot matrix screen