These are the first butt rests that truly lock the rod in, there is no way your rod can be pulled out, regardless of direction or pressure until you depress the locking pin.
To use these rests simply press the button to open the jaws, insert your rod and while the button is depressed push down to lock the jaws. On the take simply press the button and lift your rod up, as you lift the jaws will open.
To make a snug fit on any butt section you just push the relevant rubber plug into the arms of the rest so when its closed it secures your rod.
There are 2 versions available, small for abbreviated/shrink rubber butts and large for full duplon/cork handles, they are also available in Stainless Steel or Black Aluminium.