I have a soft Tailbag that I needed to mount onto my DL-650. There is a velcro strap that is used as compression/stabilization that goes around the bag. I added these 2 "brackets", which are really kitchen drawer handles that I picked up at Lowes in the hardware section which give me more mounting/securing options for the tail bag. I just removed and drilled through the rack to accomodate the screws for the drawer handles and put them on. Nothing overly scientific about it, just found the center of the rack, marked where I needed to drill and had at it. I used lock washers on the bolts to take into account for vibration. Here's a couple photo's.