Why are there wheel upgrades for Clothes Rails?

Question: Why would you need to upgrade the wheels on a Heavy Duty Clothes Rail, when it already comes with wheels?

Answer: The standard castors are strong enough to move the clothes rail around when fully loaded, but if you intend to use the rail to transport garments from one place to another on a regular basis, then the heavy duty wheels will make that much easier, and the rubberised wheels will glide much better over carpet and other surfaces. Plus there are braked versions so you can lock the wheels.

                     Braked version                                               Unbraked version