Vintage Vivitar Auto Thyristor 550FD Flash Unit for [Nikon/Canon/Pentax Tested

Vivitar 2800 Auto Thyristor Electronic Flash

Sunpak Auto Zoom 2400 Thyristor Flash Unit - Untested

Vintage Vivitar 2500 Zoom Thyristor Flash – Clean Example – Untested

Vivitar Zoom Thyristor 3500 for Hot Shoes SLR Camera Flash

VIVITAR 285 Zoom Thyristor Flash Vari-Power & exc. Battery Holders UNTESTED

Vivitar Thyristor 283 Flash for Manual Focus SLR Cameras

Vivitar Zoom Thyristor 265 Electronic Flash Gun Untested