Need more cooling in the summer or heat in the winter? This is a very affordable, very easy to install option. The equalizer has 5 speeds and can auto-adjust to your central system's timing and flow. I have one that works great in one bedroom; unfortunately the other bedroom just needs a much bigger fix. 

The package contents should contain 4 anchors. These may not be needed but please note there is only one available. 

Will fit any register 6"x12" or smaller.