Mini Fish Tank Aquarium Water Level Controller Automatic Filler Top off System. Specifications: Suitable for all kinds of water or cola water bottle or other kinds of container. Attached with 4 sizes connector for different thickness glass tank. Water level adjustable. Item Name: Water Level Controller Material: Plastic Features: Durable, Adjustable, Easy to Use Size: 6cm x 6cm x 4cm/2.36" x 2.36" x 1.57" (Approx.) Notes: You need to prepare the bottle of 30mm screw diameter and 27mm mouth diameter. Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Water Level Controller