The pro steam wand kit increases the power delivered by the steam wand on the GS3. The Cool Touch wand is convenient, but the smaller tube reduces the amount of steam available. The Pro Steam wand allows you to steam a small pitcher of milk for a cappuccino in 7 seconds. Once you have switched to the Pro Steam Wand, remember that the metal on the steam wand will get extremely hot.
Please be aware this kit does involve an installation procedure. There are videos online that show the instructions.