Highline® energy products, highly-durable and lightweight Millennium line of compression molded transformer box pads to our low-cost, stackable box pads, Oldcastle offers the quality and customization you need for any application. Oldcastle Infrastructure manufacturers two styles of fiberglass electrical distribution enclosures for utilities: compression molded and spray-up. While compression molded products are an industry standard, spray-up products offer an alternative to larger or customized parts.