The MEC Pro Check is a must-have accessory for users of the Model 600JR loader, offering enhanced functionality and ease of use. This small but valuable tool attaches to the charge bar with a bar-stop screw, allowing reloaders to keep the loading cycle in proper sequence and ensuring automatic operation of the wad guide. With the Pro Check in place, users of the 600JR loader can streamline their reloading process, making it more efficient and consistent. The installation is simple and the tool is designed for long-lasting durability, providing a practical solution for reloaders who want to make their reloading sessions smoother and more effective. Its affordable price point adds to its value, making the MEC Pro Check an essential accessory for those looking to get the most out of their Model 600JR loader.