The mount is 250 mm long so you have to turn it probably. Print in standing position with support. Here is a screencast about the design process: https://youtu.be/gL1S5TXXMjc Update #20170223 #1: I made another version which using lock clips to mount the holder to the bottom of the backpack. Update #20170223 #2: I also made a clip lock version for the 5.11 Rush 24 backpacks.