The 51400A series are square face, 4-cone, round neck ceiling diffusers with airflow pattern controllers between the cones, which change the discharge pattern from horizontal to vertical. They are available in a variety of frame styles to help meet the architectural requirements of today’s ceilings. The spacing of the inner cones in relation to the backpan result in a design possessing anti-smudge characteristics, preventing the buildup of particles on the ceiling, which is achieved by minimizing the low pressure region inherent to most 4-way directional blow diffusers. The 51400A is typically used for spot heating or cooling applications in which airflow needs to be directed vertically in order to satisfy a specific load. It can also be applied as a seasonal air outlet device; adjusting for horizontal throw for cooling in warmer months and vertical throw for heating in colder months.