We recommend you select the Walkstool model based upon how you plan to use the Walkstool and your specific needs. For example if you are planning to use your Walkstool in the lower seat position we recommend the Comfort 45. This model is the size most people prefer when using the lower seat position. The most popular selling model is the Comfort 55, it offers medium height and fits most people. If a larger seat or higher position is what you are after then the Comfort 65 is the model of choice! The Comfort series are made in Sweden and are virtually indestructable!