The SeaQualizer Descending Device are a non-invasive descending device designed to help fish recover from the effects of barotrauma. Barotrauma occurs in some fish when they are brought to the surface from deep water. This causes the air bladder to expand beyond its normal size.Physical effects of barotrauma can include: Floating at the surface Stomachs protruding out of the fish&&';;s mouth Bulging eyes Flared gills Inflated body cavities To release a fish, attach the SeaQualizer to a fishing rod or retrieval line. Next, you&&';;ll attach the SeaQualizer to the fish and lower it back down into the water. The device will trigger at the depth you set it to, releasing the fish. By bringing the fish back down to depth, naturally occurring pressure will re-compress the enlarged swim bladder causing the fish to become neutrally buoyant allowing it to swim on their own. This also eliminates all of the other physical effects of barotrauma that were seen at the surface. Release Depths by Model: Shallow Release - 30 - 50 - 70 Standard Release - 50 - 100 - 150 Deep Release - 100 - 200 - 300