Stock exhaust hangers are made of rubber, which is squishy and floppy. If you have a high-powered WRX with a large-bore exhaust, the stock hangers may not be enough to hold everything in place.
The Kartboy polyurethane hangers are the perfect solution. They're much firmer than the wimpy rubber hangers, and the polyurethane has the added benefit of much longer life.
The long hangers are the same tight polyurethane as the regular ones, but they're 3/4" longer. The length can be very helpful for exhausts that tuck up too close to back of your car. No more scorched rear bumper!