Portable, mini digital slave flash for cameras. With universal hot shoe, can work with any digital cameras. Auto Pre-Flash Sensor. Built-in Digital Slave. Usage:1. Put 2x AA batteries into the flash light, then close the battery cover. 2. Long press 'POWER' button for 3s, can startup the flash. The default startup mode is M mode. Press 'PILOT' button, can test flash light. 3. After use, long press 'POWER' button for 3s, can be powered off, remove the battery if for long periods. Model: WS-25 GN: 18 Recycle Time: 3 seconds Powered By: 2 x AA battery (batteries not included) Color: Black Material: Plastic Package Contents: 1 x flash Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.