The RM691 is a multipurpose speaker that can be used indoors or outdoors. Designed and built to withstand the rigors of outdoor environments, the RM691 will provide years of trouble-free service. A corrosion-resistant aluminum grille couples with the speaker's ABS enclosure to assure durability in any kind of weather. Adding to its versatility, the RM691 can also be mounted indoors on walls, posts, beams, or joists-wherever it's impractical to install in-wall or in-ceiling speakers. The included mounting bracket is designed for easy installation. Ideal for use with amplified keypad systems and low-wattage amplifiers, the RM691's high-efficiency design delivers ample volume with minimal power, whether you keep your music in the background or listen at party levels. Pure and simple, you get more music with Ratio .