These wheel chocks work great. They're not too heavy and bulky, but they're easy to store anywhere in the car. I have two cars, a compact and an SUV. I've broken them down so each car has a wheel chock in case I ever need that extra sense of security when parking on a slope or on ice (I live in the high desert). It's a bit tricky to get the screws they probably work best with...there weren't any instructions so maybe there's an easier way to install them...As I sometimes forget they're under my car lie, I try to drive away without taking them off. However, this proves their effectiveness as both cars stay put when I try to back up even with just one chock.