L77SDB25SC309 is a high-density D-Sub solder-cup connector designed for industrial, telecom, and standard I/O applications requiring reliable multi-contact interconnections. The connector features 78 contacts with precision formed brass contacts selected with gold in the mating area and tin plating on the termination area, housed in a steel shell with tin-over-nickel plating and glass-filled thermoplastic insulator (UL 94V-0). It is rated for 3A per contact at 250V AC/rms with a withstanding voltage of 1000V AC/rms for one minute, insulation resistance of 1000MO at 500V DC, and contact resistance of 20mO maximum. The connector operates reliably across a temperature range of -55°C to +125°C and is RoHS compliant, making it suitable for economical solder-cup termination in demanding industrial and commercial environments where high-density contact configurations are required.