What is the Quick Door Hanger bracket?

Product Description:

What is the Quick Door Hanger? This installation kit for the same cost as a pack of shims, contains a unique patented bracket system used for the easy and hassle-free installation of pre-hung interior/exterior doors. Using this quick, fail-proof system, doors can be installed accurately in as little as 5 minutes without the hard work of shimming. For beginners to pros! No shimming and zero nailing through the door jamb and frame (no nail holes to patch). Perfect door installations.