Necklace Version News Today

>> reporter: nathan and his dad would know. they put their product to the test, really to the test, placing the shark bands in the middle of chum and then swam with the sharks. >> sharks do not like this product and they want to swim away very, very quickly. so we did testing with ourselves at stake being in the water with three or four sharks. >> reporter: worn on the wrist or ankle, its a small size of a watch with the big power to repel a shark. >> peace of mind is really the heart of what we...