Fish Trap is baited with some food and as soon as the desired fish has entered the trap the closing mechanism is simply released by hand. The Fish Trap is constructed in such a way that when it is removed from the aquarium with the fish inside it remains half full of water. This method considerably reduces the stress on the fish. Dimensions app. (l x w x h) 5.9 x 2.7 x 2.7 in.