DEI is the best. Are you trying to protect expensive audio? If so DEI or the AutoPage. Clifford matrix is DEI and affordable. The Avital 3300 by DEI is the same unit but cheaper in price. The autopage is $75.00-$100.00 more but worth it. Look the autopage up. It is a complete alarm. Most others do not come with battery back up, motion sensors,dual shock sensors,temp, remote start, and to much more to list. I am a retired car thief so I know. Take my advice and fork out the money for something good.