The 257-101 is an insulated binding post designed for secure electrical connections on test panels and equipment. It features a molded Lexan polycarbonate hex head that is captivated to prevent loss, with a brass body finished in gold plating for corrosion resistance and reliable conductivity. The post includes a 10-32 thread specification and mounts in a 3/8" or 1/2" round hole, with insulated polycarbonate washers that completely isolate the post from the panel while being keyed to prevent rotation. The binding post accepts multiple connection types including .060" phone tip plugs, 1/4" spade lugs, standard banana plugs, alligator clips, or direct wire connections via solder turrets or lugs. This design is ideal for laboratory test equipment, measurement instruments, and industrial control panels where reliable, insulated electrical connections are required.