A coupling is disclosed for coupling two objects together and which includes two elements. A first element is adapted to be attached to one of the objects which is a tube by a ball-shaped member inserted into the interior of the tube. The second element is also adapted to have the other of the objects attached to it and includes a first side opening and a second opening. In order to couple the two elements together, the first element is moved sideways through the first side opening of the second element. The first opening flexes to permit passage of the first element into a cavity of the second element where it is held with a portion of the first element extending through the second opening of the second element. A cam is also provided on the first element which cooperates with the first side opening of the second element when the elements are coupled together to cause the first element to be discharged from the cavity of the second element upon rotation of the elements relative to each other.