Description of VRTX215LED: This speaker features swivel brackets that allow you to mount the speaker to your wall. Attaching the speaker to the swivel bracket is quick and easy. Simply slide the speaker on to the bracket and tighten the knobs with a quick turn.Changing the swivel position is just as easy. You simply loosen the Knobs to change the position of the speaker while it is on the bracket. IP55 rated! - These speakers are IP55 rated. This means you can install them indoors or outdoors. They can withstand heavy rain, moisture, sun,dust, and even jet streams of water hitting the speaker from multiple angles. We went above and beyond in terms of product development to get these speakers IP55 rated. These will give you amazing bass response and great full range sound quality at low or high volume. What is 70 volt - 70 volt systems are the number one choice for applications where you want to install many speakers. With 70 volt there are a lot of advantages over 8-ohm systems. One of the main advantages is the simplicity of the wiring as well as how easy it is to match up speakers with the amplifier. When we say the word tap, what we are referring to are the selectors these speakers have on them. For example, these speakers have selectable options of 2.5w, 5w, 10w, 20w. What this does is limit how many watts the built-in transformer on the speaker will allow the speaker to get from the amplifier. 70 volt systems allow you to run very long lines of speaker wire without signal loss. This is ideal when running long speaker leads. The wiring is simple. You just wire all the positive terminals of the speakers to the positive 70 volt terminals of the amplifier. The negative terminals on the speaker simply get wired to the negative terminals on the amp. You do not have to worry about impedance. The power is constant.