This is a Sunpak Auto 133S Thyristor Electronic Flash Unit. It comes in its original box and appears to be in excellent condition, ready for use. This flash unit features an "Instant Readout" Exposure Scale for easy use.

It operates on two AA alkaline batteries and offers an auto distance range of 2.3' to 33' (up to 46' with a tele-kit). Key features include aperture control 2 F/Stop Range, a brilliant wide field illumination, and a built-in hot shoe and PC cord.