Description: U-shape connecting tube can avoid blockage of CO2 flow. Easy to install and use, with no extra power required. Improve the growth and health of your plants with sufficient CO2 supply. Made of high-quality Glass materials, , safe and durable for use. Suitable for use as a decoration or provides a good source of aeration for the tank or aquarium. Specification: Material: Glass Color: Clear Tube diameter:approx.0.6cm/0.24inch XS Height:approx.11cm/4.33inch Diameter:approx.2cm/0.79inch Inner Diameter:approx.2cm/0.79inch S Height:approx.12cm/4.72inch Diameter:approx.3cm/1.18inch Inner Diameter:approx.3cm/1.18inch M Height:approx.14cm/5.51inch Diameter:approx.3.5cm/1.38inch Inner Diameter:approx.4cm/1.57inch L Height:approx.16cm/6.30inch Diameter:approx.4cm/1.57inch Inner Diameter:approx.5cm/1.97inch XL Height:approx.12cm/4.72inch Diameter:approx.2.5cm/0.98inch Inner Diameter:approx.3cm/1.18inch XXL Height:approx.14cm/5.51inch Diameter:approx.3cm/1.18inch Inner Diameter:approx.4cm/1.57inch XXXL Height:approx.16cm/6.30inch Diameter:approx.4cm/1.57inch Inner Diameter:approx.5cm/1.97inch Package Includes: 1 piece Co2 Diffuser 2 pieces Sucker