Maybe some lubricant as they are tough to convince to motion. Sometimes the device is seen on weapons with multi-tubesets but changing would seem to be slow. The bar of the "T" in the circular hole is supposed to drop in the well so maybe a small amount of downward force there while the top of the "T" will be perpendicular to the tubeset. But when the "T" bar comes into battery, it is a snap and a pretty tight fit.

Kind Regards,