Size 3 Silver. This rack and pinion overhead door opener from Vital is a silver enamelled and corrosion resistant product and features an adjustable sweep and latch speed. Being BS EN 1154 compliant, having reversible handing, a 180° angle of opening and a size 3 closing force, this product is both versatile and durable, as well as being safe to use on timber fire doors for up to 120 minute fire resistance.. BS EN 1154 compliant. Adjustable sweep and latch speed. Included in successful fire test to EN1634. Suitable for use on timber fire doors - up to 120 minutes fire resistance