These wall/ceiling built-in speakers are ideal for offices, conference rooms, medical parties, cafe, schools, bathrooms, sports halls, or even in outdoor area such as patio! These speakers can be connected to each other in a single line. You can easily attach to cavity ceilings or walls using tension springs. The loudspeaker comes with a metal grille and plastic case which is simple, compact, solid and non-fading. This set of 2 speakers is designed with 40 W RMS and 240 W peak power. The matching transformer is mounted on the back. In addition, this speaker has the tweeter to direct high frequency for optimal sound. Note: This product is just a speaker, not a Bluetooth speaker.