Not only can it be used with regular clothing, but it can also be used with various types of fabric, such as silk, kimono, sweater, curtains, carpet, etc.They do not press on hot surfaces like irons and will last longer without damaging the material. Wrinkles can be removed approximately 5 times faster than regular iron. The difference between the J-2000 and J-4000 is the size of the capacity and the "double thermostat construction" (heat retention) is included. The J-2000 without the "double thermostat structure" will take 2-3 minutes for next use.On the other hand, the J-4000 with a "double thermostat structure" will be ready for 1 to 2 minutes.