Note: This flash is not compatible with ZV-1F, A9III, A99, A77, A350, Rebel SL3, 250D, T7, 1500D, 2000D, T100, 3000D, 4000D, 200DII, X-A3, X100F, or X100T. Troubleshooting for failure to flash: 1. When using the flash for the first time, wait for the flash recycle indicator to turn green, indicating recycle is complete. If the indicator remains red or white, replace the battery with a new or fully charged one. 2. If the flash does not work, access the camera's menu and set the flash mode to "Manual / M" mode. Troubleshooting for performance issues: 1. Shutter Speed setting: This flash does not have TTL or high-speed sync functionality. It is recommended to use a shutter speed of 1/200s or slower to avoid black or white edges in images. 2. ISO Sensitivity setting: Start with ISO 100 and adjust higher based on lighting conditions. 3. Aperture setting: Begin with an aperture of f/2.8 and adjust according to brightness or darkness as needed. Long-lasting Lithium Battery: Built-in 3.8V/470mAh lithium battery provides stable performance and supports up to 440 full-power flashes with approximately 3 seconds recycle time. Equipped with USB-C charging port for fast and convenient recharging. Compact Design: The iM20 measures 1.54 x 1.5 x 1.16 inches and weighs only 31g, making it lightweight and portable for street photography and travel. Compatible Mountings: Designed for ZVE10, ZV1, A7III, GR3, GR3X, F1. Not compatible with ZV-1F. Camera Flash Type: Hot shoe Flash Sync Speed: 1/250s Product appearance and printed text may vary slightly by manufacturing batch; this does not affect functionality. Color: [Color not specified] Material: ABS Package Contents: 1 x iM20 Camera Flash (Other items not included) Note: Lighting and display differences may cause slight variations between the product image and actual color. Measurement tolerance is +/- 1-3cm.