Abstract: In the particular embodiment of an adjustable concealed sprinkler disclosed in the specification, a center strut sprinkler has a frame with an inlet opening at one end and a cap is normally retained in position over the inlet opening by a thermally responsive strut assembly extending between the cap and the other end of the frame. A deflector is supported by pins having tapered enlarged heads to be received in correspondingly tapered sockets formed in the frame. To retain the deflector in a retracted position and urge the strut assembly away from the cap-retaining position, a wire spring extends from an enlarged head of one of the deflector retaining pins around the strut assembly to engage a portion of the frame.