Body Flex is resistance training tool. Basically it is a long 2 piece bar that connects in the middle with a heavy duty rubber band that inserts into both ends.
I purchased Body Flex for it's ability to do exercises on a wide variety of body areas (buns, thighs, stomache, back, arms and legs). Another feature for me was the fact that it is extremely portable and very easy to store and put back together again...the whole thing fits into a bag about 1 foot by 6 inches.
Once I obtained the device, I loved it even more. Although it comes with a video and book, another great feature I really appreciate is the exercises are labeled and "demonstrated" with pictures right on the rod! How easy is that?
One word of caution though...use only as directed. My husband was using this just after I purchased it and somehow the rubber band slipped (not sure how) and snapped into his face. He laserated his cornea.