Built-In 2.4 GHz X Wireless Radio System Compatible with Canon E-TTL / E-TTL II Guide Number: 197' at ISO 100 Zoom Range: 20-200mm Tilts from -7 to 120° Rotates Horizontally to 330° Wireless Master/Slave TTL Functionality Recycle Time: 0.1-2.6 Seconds High-Speed, 1st & 2nd Curtain Sync Runs on Four AA Batteries