Through Shaft Mount Overload Safety Devices - Type B > Through-Shaft Torq-Tenders with Actuating Disc - Type BD

Through-Shaft Torq-Tenders with Actuating Disc - Type BD

Click image to enlarge
The Through Shaft Mount Type B is intended to have a shaft pass though the full length of the Torq-Tender. A component such as a sprocket or sheave is mounted externally on the Torq-Tender. 

The BD model comes with an actuating disc that is forced out for immediate indication when overload occurs.  This feature is typically used with a (customer supplied) limit switch for shutdown or warning.