X2T-O TTL wireless flash trigger works with camera flashes, outdoor flashes, and studio flashes with built-in X wireless radio system. It delivers stable, reliable real-time signal transmission for photographers with varied lighting demands. Key features: - TTL capable operation for accurate flash timing and power control within the X wireless radio system. - User-friendly design: LCD display with clear readout; 5 group buttons and 3 function buttons for quick settings; all keys backlit for easy operation in low light. - Bluetooth support: connect your smartphone or tablet (iOS or Android) via Bluetooth after installing the Photo app to control flash mode, power output, modeling light mode, and flash beeps. - Quick-lock hot-shoe; minimum power output settable to 1/256 in 1/10 step; 5 groups, 32 channels, and 99 wireless ID settings to limit interference from nearby systems. Use scenarios: - Studio portrait setup with multiple off-camera flashes for balanced lighting. - Outdoor location shoots needing remote control of key, fill, and rim lights. - Event photography demanding reliable wireless triggering across several flashes.