Clear Peep Weep Vents Pack of 100 Low profile invisible tunnel weep vents. Suitable for commercial and domestic use. Satisfies NHBC standards. British made manufactured to BS EN ISO 9001. Dimensions: 105 x 62 x 10mm. The product can be slotted between two bricks and mortared into position. It provides an unobtrusive ventilation & drainage point for the cavity behind. Other colours available in our shop. The G951 Peep Weep provides an unobtrusive solution to cavity wall drainage requirements. Thanks to a mortar key, this product can be adhered to the building fabric and its external rib will aid positioning. The rib surrounds a 62mm high opening to prevent mortar blockage from within the cavity. The weep’s protective hood is designed to guard against blockage during installation and stops penetration of wind driven rain. The exit hole is ample for water drainage but small enough to prevent entry of large insects.