The WAGO part 880-831/999-940 is a 4-conductor through terminal block designed for use with 4 mm² wires. It features a convenient test port for easy troubleshooting and maintenance. This terminal block does not have a shield contact and includes center marking for quick identification. It is suitable for DIN-rails of sizes 35 x 15 and 35 x 7.5. The CAGE CLAMP® technology ensures a secure and reliable connection for 4.00 mm² wires. This terminal block comes in a sleek gray color, making it a versatile choice for various applications.