After a knee replacement that limited exercise, I took some swim classes, using class aids. They were helpful but I wanted my own to use anytime I went to the pool. I ordered this model online. This particular one has choices in how you wish to use it by pushing the four float pieces to one side or the other or a combination of locations. It can be used by placing under the armpits with arms free up and over the bar to help move you forward as you try different kicks with your legs. Since I wasn't in shape to use just my arms and legs themselves, this bar helped me save energy by just using my legs to kick from one end of lap lane to the other and holding the bar out in front of me with face close to water or doing swimmer's breathing. I also used the bar to allow me to do whip kicks in verticle position by holding the bar straight down in front of my body in water just deeper than my height, straight armed, and did the kicks. I get a good workout for a longer period of time only working my legs to strengthen my knee without the added energy-zapping arm movements. It's a great water exercise floatation aid!!!