The SF-4000 Bounce Zoom Slave Flash from Vivitar can be used as both a normal bounce zoom flash with tilt up to 90° or as a slave. This flash features 4 slave modes that allow it to work with cameras that fire their built-in flash immediately or cameras that have a single or multiple flash red eye reduction system. The SF-400 has a multi-angle 3-position zoom head that covers wide angle, normal, and telephoto distances. It runs on 4 AA batteries.