A weatherproof electrodynamic exciter that can be placed virtually anywhere, Dayton Audio's HDN-8 literally makes any surface "ring". The product is screw-mounted using the screw head molded into the speaker. It's ideal for applications where speakers can't be placed for visual reasons, or for outdoor locations, or for vandal-proofing. In fact, thanks to its hermetically sealed design, it can be easily integrated into an indoor bathroom or outdoor terrace. The large-thread metal stud is easy to install in wood, fiberglass or plastic. This product can be used like a conventional loudspeaker, thanks to its 8-ohm impedance.