The "Wanger" was developed by Sea Search of Virginia, a Reef Ball Authorized Contractor, to make deployment of Reef Ball Artificial Reefs easier. It has been patented by Sea Search and has a variety of marine construction applications. Basically, when the material is lowered by the crane to the sea floor, it automatically releases when the weight comes off the cable yet is save for moderate sea conditions.This model would need to be printed in a few parts to actually work. When you suspend something from ropes with this thing (we use with a crane to deploy heavy concrete artificial reef modules) the device will relase automatically when the concrete is set down on the ground (in our case the sea floor). The company that made these is now out of business.