ive made this model mostly because i had no space on my walls and didnt want to directly screw a hook into my kallax. Ive left no hole for a hook or screw so that you can pick your own size and place for it. 

To print you will need:

• 4 kallax mounts
• 2 joints
• 1 vertical mount
• 4 horizontal mounts

I printed this in pla but i would recommend printing it in something stronger like abs, petg, etc. I recommend glueing the horizontal mounts to the kallax mounts for extra durability