An automatic fire protection sprinkler includes a sprinkler body having a passage with an inlet end and a discharge opening. A pair of sprinkler arms extend from the sprinkler body. The pair of sprinkler arms each include a radially inwardly extending leg including a threaded bore for receiving a compression screw. The pair of sprinkler arms each include a radially outwardly extending leg each defining an aperture therein. An outlet closure assembly includes a closure element that selectively blocks the discharge opening of the sprinkler body and a trigger assembly including a yoke that engages the compression screws and a glass bulb that extends between the yoke and the closure element. A deflector is coupled to the sprinkler arms by a pair of support pins that are received in the apertures in the radially outwardly extending legs of the at least two sprinkler arms.