With little holes, it is easy to release and sink to the bottomIt is used to catch the snails which may influence the apperance of fish tank.Open the lid and push the fishing line into the stomata base.Made of clear plastic, it is easy to clean and will not pollute the water.Catch snail and will not do harm to fish and plants.This item is a special tool for catching snails. It is made of clear plastic and it is easy to assemble. There are holes on the lid for the fishing line to go through. And then you can connect the lid and the base. Just put it into the fish tank and wait, it will not let you down.Material: Plastic.Colour:BlackSize: 8 x 8 x 8 cm.Package Including1 x Snail CatcherOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.