For each post mount you will need a 1.75″ long 1/4 x 20 screw or bolt, a washer (fender preferred if there is room) and a 1/4 x 20 nut.
Start by drilling a 1/4″ hole through the coro where the post mount will be located. Then prep the mount by inserting the 1/4 x 20 nut into the mount. It’s often easiest to temporarily insert the screw from the bottom of the mount and threading the nut onto the screw. As you tighten the screw it will pull down the nut and seat it in place. To install the mount insert the screw with the washer from the front of the prop and thread the screw into the mount on the back. Then orient the mount as desired and tighten down on the screw to hold everything tightly in place.
Note: The 1.75″ screw / bolt is an odd size and is not commonly carried by the big box stores. This size is required to maintain a constant mounting height across all of our mount designs. If not available, you will need to either cut a 2″ size down to 1.75″ or predrill the EMT / PVC so that it can accept the longer end of the screw or bolt.