Apparatus are described for mounting an object to a structure having a railing. The apparatus includes a base attachable to the object and configured for placement on the structure proximate the railing. The apparatus further includes an adjustable compression mechanism positioned between the base and the railing configured to secure the base to the structure with a selected force. The mechanism includes a first plate on the base, a second plate movable relative to the first plate for producing a selected height of the mechanism and a threaded member attached to the first plate and the second plate. The threaded member is configured to move the second plate relative to the first plate to achieve the selected height and apply the selected force.