MTJ-663X1 is a modular telephone jack connector designed for PCB mounting applications. It features a PBT insulator rated UL 94V-0 with black color and phosphor bronze contacts with gold flash over nickel underplate on the contact area and tin over copper underplate on tails. The connector operates at a maximum voltage of 125 VAC with a current rating of 1.5 Amps max and contact resistance of 20 ohms max. It offers an insulation resistance of 1000 Mohms minimum at 5.00 VDC and dielectric withstand voltage of 1000 VAC for 1 minute. The operating temperature range spans from -40°C to +85°C, making it suitable for various telecommunication and data communication applications.