This Vivitar Auto Thyristor 550FD flash is a reliable and functional accessory for any camera setup. It has been thoroughly tested and confirmed to be in working order. This flash is perfect for capturing stunning photos in low light conditions, and is compatible with a variety of camera models. With its brand name and model number, you can be assured of the quality and performance that Vivitar is known for. Add this flash to your collection today and take your photography to the next level.