In Reply to: PTO shield posted by Gary Ostby on February 28, 2017 at 19:17:23:
They provide the fastening lock for the shaft covers that were/are used on many PTO driven implements. The shaft covers self adjust lengthwise when in use. Each end has a spring loaded pin and flat handle. The pin slides into the notch and then the handle pivots 90 degrees to lock in front of the "tabs". Hopefully someone has a picture.