Play outside. Play smart - Voyager Rock Speakers are each designed to resemble natural rock formations and provide advanced audio solutions for "outdoor soundscaping" in all types of environments. Single Channel Speaker - the RK5 is configured as a single channel speaker and includes a 5-1/4" bass unit and 3/4" tweeter. Use two RK5s to support stereo left and right channels. Their sound is contoured to provide the best performance in open air environments. They blend perfectly with the other Voyager series models. Your choice of rock formation styles - New England Granite or Sandstone. Think outside the house - Boston Voyager Rock Speakers are designed to blend gracefully with virtually any outdoor décor and are specially voiced for open-air environments. These tough and durable outdoor speakers feature rustproof hardware, grilles, and connectors and are designed to withstand the harshest weather and temperature extremes. Each model also features a recessed weatherproof cavity on the bottom that can house a 70/100 volt transformer (can be purchased at an electronics retailer) for use in light commercial installations.