Overall Size: 411 x 18.5 mm Overall Slot Size with 20 mm Bridge: 367 x 13 mm Projection: 20 mm features: Trickle vent Surface mounted internally Deflects air up or down, or both Sculpted finger recess Matching screw covers included Equivalent Area (EA) of 2200 mm sq Free area 4045 mm sq Tested in accordance with BS EN 13141-1:2004 (air flow, air leakage and weather tightness). Acoustic performance tested in accordance with BS EN ISO20140-10:1992, BS EN ISO140-10:1991 and single figures to BS EN ISO717-1:1991. PBTP (UV Stable) and POM