Abstract: An adjustable end pin for a string bass or cello. The end pin extends through a hub having a cavity containing a jam plate with a central hole through which the pin extends. The jam plate is normally biased by a spring to an angular position relative the pin to jam or lock the pin to the hub. However, upon pushing the collar to exert lever action on the jam plate to move it towards a right angular position, it will unlock the pin and allow incremental pulling out thereof from the hub to provide incremental adjustment of the height of the instrument from the floor.