A post socket includes a housing, a compressible sleeve within the housing, the sleeve being moveable between a first position in which the sleeve has a first internal width and a second position in which the sleeve has a second internal width, a linkage pivotably connected to the sleeve, and an actuator for actuating the linkage to move the sleeve from the first position to the second position to grip a post therein, the linkage including a linkage body connected to the actuator, the linkage further including at least one arm including a first end and a second end, the actuator being configured so that its actuation moves the linkage body to thereby move the first end and the second end of the at least one arm and thus move the sleeve from the first position to the second position.