The 10-580902-20Y is a protective metal cap from the Amphenol GT Series, specifically designed for size 20 receptacles. It features a durable black zinc cobalt finish and is engineered to seal the front of various receptacle types, including GT00, 01, 02, 020, 030, and 070. The cap has a maximum diameter (N) of 1.594 inches and includes an attached retention chain with an approximate length of 5.000 inches to prevent loss. This accessory is essential for protecting unmated receptacles in harsh environments such as rail and mass transit, ensuring connector integrity and longevity.