Hand paddles help you learn the right angle and position of hands when practicing proper swimming technique. There are many different kinds of paddles some of which are also used to build upper body strength. Here is a one example of hand paddles that you can print. Novice swimmers should start with smaller paddles to prevent injury as training hard with big paddles combined with bad technique can cause heavy strain on shoulders. http://en.wikipedia.org/wiki/Hand_paddle I have a design for finger paddles, too. Thing number 683690. Paddles in the photos (including a hand for scale) are prints of the small version. Normal version is similar, but larger.Print one for each hand. Just two copies, or if it matters is the botton side or top side of the print facing your hand, then one should be a mirror image of the other. Just like your hands - thumb being on the other side. Paddle is tied to a hand from any of the holes with a rubber tube, rubberband, piece of string or maybe even a zip tie or something else. This kind of paddles usually come with a rubber tube that sticks to the small holes in the paddles. I used pieces of a old road bike inner tube as attachments. I just forced those through the holes on the paddle. Easy to do (using pliers) and works great. If a little of extra rubber is left dangling on the other side of the paddle, it doesn't really matter. That's how it works with commercial paddles too.