Lamp transformer for use in 6.6 A airfield constant-current lighting circuits. Design based on a low-loss toroidal core, potted in polyurethane with high-quality outer plastic encapsulation and IP68 outlet seals. Transformer suitable for burial directly in the ground. Encapsulation and outlets are resistant to acid and alkaline soils, as well as to chemicals commonly used on airfields such as oils, fuels, de-icing fluids, etc. The materials used are also termite- and rodent-proof. Designed to meet the FAA Specification AC 150/5345-47 and IEC 61823.