The 851 LOCK Micro-Plug® is a subminiature, 2-conductor phone plug designed for secure connections. It features an integral threaded collar that fastens to the bushing of a mating jack, requiring at least .05 inches of exposed thread to lock securely. This plug is constructed with a nickel-plated copper alloy body, a black anodized aluminum handle, and has an electrical life rating of 5,000 insertion/withdrawal cycles. It can withstand 250V AC, has an insulation resistance greater than 100 megohms, and operates in temperatures from -20°C to 65°C. Its secure locking mechanism makes it ideal for critical applications such as medical and sensitive scientific instruments.