Sharkbanz: a shark-repellant wristband

Theoretically, the Sharkbanz, a wristband containing a magnet, will keep a shark from attacking you if you wear it while you’re in the ocean. As you might imagine, it doesn’t work. Here’s a video of a shark eating a Sharkbanz:

Adding insult to injury, customer reviews mostly agree that it’s poorly made and falls apart easily, which must have taken considerable effort considering the low cost and ease of manufacture of a rubber wristband.