State-of-the-art, the 48 AF-1 allows photographers to stay current and effortlessly make firmware updates via the internet and the flash's unique USB connection. The flash features a powerful guide number of 158 and for added versatility, is powered by four, readily available AA batteries. TThe 48 AF-1 C is designed to support Canon’s E-TTL and E-TTL II technology. The 48 AF-1 is fully compatible with TTL digital remote systems and can also be operated as a TTL slave unit that can be controlled by the camera's built-in commander mode, a manufacturer’s flash with master capabilities, or from a Metz 58 AF-1. The 48 AF-1 also features an auto zoom head from 24-105mm that can be set to match the camera’s sensor, a full bounce and swivel reflector head, a built-in wide angle diffuser for 18mm coverage, and of course, full manual control with 12 partial light output levels.