The 2138-2 is a red Standard Banana Jack to Miniature Banana Plug Adapter permits standard banana plug to be used with equipment having miniature banana jacks. Banana jack is made of brass (as per QQ-B-626) with nickel plated finish (as per QQ-N-290) and moulded ABS insulation. Miniature banana plug has heat treated beryllium copper spring with nickel plated finish (as per QQ-C-90).