Product Description Multi-function pre-formed products to guarantee a reliable discharge of water wherever water could collect inside an external cavity wall built from standard brick, block or stonework.Cavity lengths can be built up using the 1144 weep extension unit ( 50mm):compatible with both the 1143 and TW1 weep ranges.A full size wall weep vent, which corresponds with the height of standard brick, block and stonework.Free airflow area of 165mm² per unit.Featuring an integral front grille to prevent the entry of large nest building insects into the cavity.
