Insulation recess box large 545X300X150 protect transformers, fixtures and building parts against overheating. The boxes are made of flame retardant red polypropylene. They are suitable for mounting on normally flammable materials such as wood. To comply with safety standards, a fixture of max Wattage of 50W can be used. Other fixtures can also be used in combination with these boxes, provided that the minimum recess dimensions and maximum Wattages specified for those fixtures in insulated ceilings are respected.