The Littelfuse CT-0400-D20 is a 400:5 current transformer designed for use in electrical metering applications. This 2-inch window donut-style transformer is constructed from high-quality materials to ensure durability and reliability. It features a compact design that allows for easy installation in tight spaces. The transformer is rated for a primary current of 400A and a secondary current of 5A, making it suitable for various monitoring and protection applications. Compliance with industry standards ensures compatibility with existing systems, providing peace of mind for users.