This is new type of pull buoy system that is easy to use and does not fall off.  They are great for all strokes and fasten with velcro.  You can develop upper body strength without worrying about sacrificing rhythm or your technique.  You can focus on pulling and not on keeping your legs squeezed together.  They encourage long-axis rotation and develop proper swimming angles and balance of stroke.

How to Apply and Use RANGS Independent Pull Buoys
The Smarter Pull Buoy
Description:
RANGS JR are neoprene independent pull buoys designed by coach and  
biomechanist Steve Friederang that wrap around each leg and hold with  
velcro to free you to swim naturally. Each buoy conforms to your  
legs, providing the most efficient lower body support. This support  
then allows you to settle into a front-end dominated rhythm as you  
develop upper body strength. So, rip your turns, even kick off the  
wall if you want, knowing that the RANGS independent buoy system will  
not fall off. RANGS can be used for all four strokes, providing much  
more natural rotation in freestyle and backstroke, and creating a  
more streamlined body position in breast and fly. Better for rhythm.  
Better for balance. RANGS: simply better pull buoys.

        How to Apply:
        • RANGS have two sides -- the outside which allows the hooks on the  
velcro to comfortably adjust to any diameter leg, and the inside, a  
special neoprene pattern that keeps the buoy from slipping when you  
swim or make turns.
        • RANGS also have a front and back -- where the foam conforms to  
your leg and provides lift. Typically the back side is the side  
facing the sky or roof and the front faces the bottom of the pool.  
Reversing this application decreases stability and increases roll.  
Experiment to see which is best for you.        
        • Place the RANG with the neoprene sticky side toward your leg. Most  
people place the RANGS as high up the thigh as possible, but  
experiment to find your ideal center of buoyancy.
        • Wrap as tightly as comfortable to ensure the buoy won't slip. If  
it does slip, stop and pull it tighter and lock the velcro in place.
        • Do the same with the other RANG for the other leg.
        
        If you are a swimmer or coach interested in making sure your legs  
don't bend during the recovery part of the kick in dolphin and  
flutter, place the foam of the RANG behind the knee and wrap tightly  
with your leg straight. You will have to kick from your hip both on  
the upsweep and the down-sweep. Most swimmers learn from this  
feedback and build the muscles and muscle memory for a proper kick in  
a short time, and simply swim faster from then on.
Principles:
RANGS JR allow smaller swimmers with any body type to customize ideal strokes  
and gain upper body endurance without changing stroke mechanics. This  
makes your practices more efficient and more effective, and helps  
reduce injuries to shoulders and knees which are often negatively  
affected by poor body position (ie: "flat" strokes). RANGS also help  
you align with the principles of summation of forces and specific  
adaptation to imposed demands (the SAID principle).

Rinse with fresh water after use and store in your Finis mesh bag in  
between practices.

        How to use:
         For Freestyle and Backstroke:
        • RANGS JR encourages rotation. So forget your habit of staying flat  
when squeezing the old fashioned buoys between your legs. Now you can  
and you should rotate 40-50 degrees at the shoulders and hips as you  
pull or swim in freestyle and backstroke. This will provide a great  
advantage over those who are squeezing their knees against a buoy.
        • Focus on pulling, not on holding your thighs together. Allow your  
body to rotate into an ideal position to pull and feel for your ideal  
center from front to back as well as from side to side.         
        • TURNS: Pick up your kick and perform a single dolphin coming into  
the wall to raise your hips and pull with your arms. You should be  
able to see the front wall halfway through your flip while upside  
down and your knees should be bent allowing your jump off the wall  
with full force the instant your feet make contact.
        • Focus on snapping your turns, not on retrieving your pull buoy.  
Your knees should be shoulder width apart and you should explode into  
and off the walls. Get your hands in streamline position and your  
elbows locked with your body in alignment on its side BEFORE the  
balls of your feet bounce onto and leap your body off of the wall.  
Dolphin if you wish, again naturally, which means your knees will  
flex open and shut and you kick up and down.
        For Breaststroke and Butterfly:
        • Using RANGS lifts your hips and shifts your center of buoyancy.  
You can adjust this by attaching your RANGS up or down your leg into  
the perfect position. Have a coach give you feedback as to where this  
perfect center is. Even when your legs are exhausted, you can work  
your stroke because your hips are where they are supposed to be. You  
may use RANGS in full stroke fly or breast or you may focus totally  
on upper body power or endurance.
        • RANGS JR , used properly, encourage front-end swimming  in all four  
strokes. You should feel as if you are swimming or pulling down-hill,  
and underwater video should show your hips in exactly the correct  
position allowing you to conserve energy and to develop power and  
endurance in the right muscles.
        • RANGS are perfect for senior swimmers, triathletes, masters, age  
groupers , fitness swimmers, water polo players, lifesaving  
applications and even teaching applications (though they are NOT a  
lifesaving device).