Canon speedlight 166A.
The Canon 166A speedlight is a small hotshoe flash. Ideal for cameras without a built-in flash. The speedlite will automatically set the shutter speed and aperture with the A-1, AE-1 and F-1 (in shutter priority mode) It will also automatically set the shutter speed (but not the aperture) on the AL-1, AV-1 or AT-1 and a manual sync on other cameras. IT has an ISO range from 25 to 800
Guide number. 66 at 100 ISO.
Head type, Fixed head. With zoom capabilities from 0.5 meters to 7 meters.
Modes; Auto TTL with manual aperture settings
Power source; 4x AA batteries.