4 core drill vents are designed for use when ventilating a gas appliance or supplying general through wall ventilation. Using a standard 4 core drill, the system can be fitted quickly and easily in both new build and refurbishment situations. Main Features: 100mm (4”) Core drill ventilator Easy to install with telescopic movement and louvered grille Expands 100 to 195mm (4 to 73–4 ”) Takes extension tube BM 811/B to extend further Plastic Brown external Brown internal Technical Specification: Diameter: 100mm Length: 100mm - 195mm Construction: Plastic 1 Year Guarantee Included
