Magnetic shark repellents utilize permanent magnets, which exploit the sensitivity of the Ampullae of Lorenzini in sharks and rays (electrosense). This organ is not found on bony fish (teleosts), therefore, this type of shark repellent is selective to sharks and rays. Permanent magnets do not require power input, making them practical for use in fisheries and as bycatch reduction devices. Sharkbanz, released in 2014, is a wearable commercially available device intended for recreational users. Its manufacturers cite numerous scientific papers which support the effectiveness of permanent magnets in a range of contexts. A field study of a range of shark deterrents in 2018 found that Sharkbanz were ineffective when used in a temperate oceanic setting with berley-attracted Great white sharks.