Horizontal, Recessed Horizontal Sidewall & Vertical Sidewall Sprinklers• Light hazard/Ordinary hazard • 3 mm bulb • Designed for use in applications where aesthetics must be considered or where building construction makes the installation of standard pendent or upright sprinklers impractical • Vertical sidewall sprinkler can be installed in either the pendent or upright position along a wall or the side of a beam and just below a smooth ceiling.