Armanov Quick Disconnect fits on the RL550, XL650, XL-750, and Super-1050 powder measures. It is specially useful In combination with Clickable Armanov powder  knob. So you can reuse powder measure on other tool-heads and adjust powder quantity with simple clicks. Quick and tool-less removal and installation of Dillon Powder Measures.Installation is super simple. Just remove original half-ring retention and install Armanov Quick Disconnect for Dillon. It has two internal springs and allows quick change of powder bar from one toolhead to another.