Moon clips are a reloading device/method that makes it much easier to load a revolver cylinder with all your cartridges at one time. No fumbling, while loading your cylinder with rounds individually and possibly dropping some of them on the ground. No speedloader to pick-up off the ground after you load your revolver cylinder.
Alfa Proj 9mm Revolver Moon Clip 6-Shot
Moon Clips are .032 thick Stainless Steel.
These clips fit most 9mm brass.