From time to time over the years, a few of our customers have requested something like this - typically for higher speed and larger transducer applications.  This will lock your transducer arm at an unmovable 45° detent.

 

Video link:

 

https://youtu.be/pPTFsgvZoZ0

45° Transducer Arm Lock

SKU: PLA00027
$14.00Price