Answer: 2.5 refers to a three-layer net that can probably catch fish weighing 3-8 weight. This kind of three-layer net is usually a crucian carp net. The three-layer net is very good. Fish usually won't break free when they get on the net, and they will get tighter and tighter.

If it is a net for catching silver carp and bighead carp, it must be at least a three-layer net with more than 5 fingers. In this way, you can at least catch silver carp and bighead carp weighing more than 3 kilograms. To fish with this kind of net, you need to take a fishing boat into the water, so you must pay attention to safety.