THE BUDDYBAR II JUST PLACE THE SPRING LOADED HEAD UNDER THE DOOR KNOB, USING YOUR FOOT, TAP AGAINST THE KICK PLATE TO SECURE YOUR BUDDYBAR, THATS ALL THERE IS TO IT, IT TAKES ONLY SECONDS TO RELEASE THE BUDDYBAR, JUST KICK THE FOOT IN THE OPPOSITE DIRECTION. THE BAR IS EASY TO PLACE , AND TO REMOVE, BUT AT THE SAME TIME IT IS VERY SECURE WHEN INSTALLED. THIS BAR IS NOT ADJUSTABLE ON A STANDARD DOOR, THE DOOR KNOB IS POSITIONED 36" FROM THE FLOOR, SO WITH THAT IN MIND, PLEASE MEASURE YOUR DOOR BEFORE YOU PLACE YOUR ORDER. THIS DOOR JAMMER WILL WORK ON DOORS WITH THE DOOR KNOB POSITIONED BETWEEN 34"- 36.5" FROM THE FLOOR ----------------------------------- THE BUDDYBAR AT THE TOP OF THE PAGE, WILL ADJUST FROM 36"-51"