Black Tunnel Weep Vents Pack of 25 Low profile invisible tunnel weep vents. Suitable for commercial and domestic use. Satisfies NHBC standards. British made manufactured to BS EN ISO 9001. Dimensions: 100mm x 64mm x 10mm. The product can be slotted between two bricks and mortared into position. It provides an unobtrusive ventilation point for the cavity behind. Other colours available in our shop.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 Manufactured to BS EN ISO 9001 and BS EN ISO 14001. Meets British standards; BS5250, BS8000, BS5628, BS8215. Satisfies all NHBC requirements.Complies with all relevant Building Regulations - Approved Document C.