The MD-40J is a 4-pin Mini DIN connector from Same Sky (formerly CUI Devices) designed for reliable low-voltage signal and power transmission. It features a recessed face design with integrated strain relief, and is constructed with a copper shell (nickel-plated), brass pin contacts (silver-plated), and a Nylon 6 + glass fiber insulator for durability and electrical performance. The connector is rated for 100 Vac or 12 Vdc input, with a maximum current rating of 2 A at 100 Vac and 1 A at 12 Vdc, and maintains contact resistance below 30 mO. It offers an insulation resistance of 50 MO at 250 Vdc and can withstand 250 Vac for 1 minute, with an operational life of 5,000 insertion/withdrawal cycles over a temperature range of -20°C to +85°C. The MD-40J is ideal for industrial control systems, audio equipment, and consumer electronics requiring compact, reliable interconnection with RoHS compliance.