High throughput cavibricks are designed to be used singularly or can be locked together to form larger brick-sized ventilating units. When connected to a cavibrick the combined length is sufficient to accommodate all popular cavity wall widths. We recommend sleeves are protected with a cavitray where they pass through the cavity, to comply with NHBC/best practice. Sleeve attachments to provide ventilation to specific areas. Properties Length: 300mm. Width: 75mm. Height: 225mm. Material: polypropylene. Colour: black.