Repel Sharks: Shark Deterrent Mini Canister Shark Repellent - designed to reduce interactions with sharks - uses semiochemical developed by the world-renowned shark scientists Dr. Eric Stroud and Dr. Patrick Rice from the Shark Defense research group - The only scientifically proven chemical shark deterrent Sufficient repellent for 1-2 sharks / Perfect for spearfishing Not harmful to sharks or other marine life, does not affect bony fish (teleosts) Affects olfaction (smell) and gustation (taste) in a wide variety of shark species (including all species that commonly present a serious danger to humans) Aluminum, Inverted Release/Manual Trigger, 150 psi, can be taken to a depth of 50 feet