I picked this up at an estate sale. The flash unit charges and "tests" with the TEST button, while powered off the rechargeable battery. There is no way to run the flash unit off of mains power, although I do see an external jack marked "batt." Includes rechargeable battery, battery holder for AA style cells, charger, sync cable, and manual. No further testing could be done. As such, I am selling this item as-is. Sunpak Auto 522 Specifications from the web: Based on the provided search results, here are the key specifications and features of the Sunpak AutoThyristor 522: Flash Type: Auto-Thyristor, Handle-Mount Type Compatibility: SLR cameras (film and digital) Features: Measures light reflected back to determine correct exposure Requires setting of ISO and aperture (no TTL or pTTL) Can be used with legacy screw-mounted lenses Has a slave unit for coordinated flash triggering Can be used with multiple cameras (but may require workaround for triggering) Has a voltage protector (recommended for use with modern DSLRs) Dimensions: Not specified Weight: Approximately 4 lbs 12 oz (including battery pack and accessories) Power: Battery-powered (requires 6 alkaline batteries or rechargeable nickel-cadmium batteries CL-2) Sync Cord: Available (but may require voltage protector for use with modern DSLRs) Slave Unit: Available (allows coordinated flash triggering with multiple cameras) Thank you for looking...