Aquarium water changer: the amount of water absorbed by dropper can be adjusted by controlling the strength of grasping the dropper end. Clear water fish tank: cleaning tool: it can help you clean the waste in the corners and hidden places quickly, you can stir the waste at the bottom of the tank and suck it. Aquarium feeder: suitable for chemical use dropper or pipette water changer or fish tank cleaning. Fish dropper: wide range of uses: this dripper has a variety of applications and can be as a lab chemical dripper or pipette, water changer or fish tank cleaner. Easy to use: the water absorption of the dropper is determined according to the size of the fish tank; the water absorption of the dropper is adjusted by controlling the strength of grabbing of the dropper. Colour:As Shown Material:Plastic Package Contents: 4 * aquarium water changer Only the above package content, other products are not included. Note: Light reflection 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.