The Speed Loader Box lines up the rounds to quickly snap the empty Speed Loader on fully loading it.
This works with both the Long Rifle Rounds and Magnum Rounds.
If you are shooting .22 Shorts you will need to add a "spacer" to the bottom of the holes so the .22 Short is tall enough to snap the Speed Loader on.
I use 3/16" round wood dowel material (Chop Sticks work) cut at 1/4" long and drop them in the holes you want to load for your NAA .22 Short. The "Spacers" can be removed by tipping the box upside down.