The Marathon/Kulka 411-GP-21 series terminal blocks are designed for reliable electrical connections in a variety of industrial applications. These single-row terminal blocks offer flexibility with 1 to 23 poles and a standard 1/4" center spacing. Constructed with a phenolic base and plated brass terminals, they provide durability and efficient current transfer. The open-back design requires an insulator strip for optimal voltage rating, and various hardware options are available to suit different mounting and connection needs. UL Recognized and CSA Certified for added assurance.