Extendable Cavity Wall Sleeve Vent Brown Air Brick 9 x 9 Inch Ventilation for heating and gas appliances with integral wind baffle. This vent is to increase the airflow in a room to eliminate condensation with this sleeve vent for heat producing appliances. Extends to suit wall thickness of 190mm - 335mm. Additional G935 extension sleeves available in our shop. Finished with 9" x 9" louvre vent for internally and air brick for externally. Aesthetically pleasing and simple to install modular system. Provides a maximum equivalent area of 15200mm² of free air space. Meets NHBC requirements for the control of condensation in buildings. Manufactured by Manthorpe Building Products with the exception of the air vent. Different colour air bricks available in our shop. Use To provide ventilation for heat producing appliances To provide background room ventilation Individual ventilation sets can supply up to maximum appliance rated input of 18kW (61,500 Btu/h) For new build, refurbishment and remedial workFeatures & Benefits Aesthetically pleasing and a simple to install modular system Excellent airflow properties Independently tested by BRE Offers reduction of draughts and light compared to basic through wall ventilation Internal finish with open louvre grilleRegulations & Standards BRE Digest 17 BRE Digest 262 Building Regulations C4 NHBC Standards 5.2BS 5250:2011 Control of Condensation in buildings