Easy-Trim Clear Weep Vents Pack of 50 Ventilation and essential drainage for the internal wall cavity. British Made. Satisfies NHBC Standards. Manufactured to BS EN ISO 9001. Dimensions 100mm x 65mm x 9mm. Available in a range of colours in our shop. The product can be slotted between two bricks and mortared into position. It provides an unobtrusive ventilation point for the cavity behind. The vent has a baffled grille to prevent the ingress of driving rain and wind whilst incorporating an insect grille and drip lip. This grille is sized to keep out large insects but is wide enough that it will not be blocked by debris, paint or water droplets.Use Any situation where water must be discharged from an external wall, e.g: At ground floor slab level. Within cavity tray systems. Over external lintels. Where a cavity must be ventilated On external walls - 100mm or more in thickness - built from brick, block or stone. Features & benefits Purpose made and pre-formed to guarantee reliable discharge of water. Less prone to inadvertent pointing-up than weep holes formed by simply leaving the perp. joint open. Integral front grille prevents entry of large nest building insects into the cavity. 4mm wide front aperture prevents entry of large nest building insects into the cavity. Range of colours to blend with brick or mortar colour.Quality Satisfies all NHBC Standards 2006 Edition. Manufactured to BS EN ISO 9001 : 2000. Complies with all relevant Building Regulations. Meets all relevant British Standards.