Metal shell options are also available in a number of orientations, allowing designers the ability to select their preferred way of securing the connection. Shell styles include threaded, quarter-turn (twist lock; a triple-start ACME thread typically found in 38999s), as well as a triple-key breakaway offering. When combined with a jacketed cable, these connectors are available in an IP68 watertight seal in both inline and panel mount configurations. Nickel-plated brass or aluminum are the shell materials and plating most commonly stocked; however, other optional shell materials can be special ordered.