the derlin collar screws in and the silver plated center pin floats. I screw in the rba, tighten the collar til just snug and make sure the center pin is pushed all the way in. Then unscrew the bottom pin to adjust for batter height. I like to keep it as snug as possible, so I'll loosen the rba and snug up the end caps then tighten my rba. I have the 26650 ToL, and like it loads. You generally only have to mess with it if changing to a different brand batt. MNKE's are taller than the Sony's.