This device allows you to connect 1L and 2L cylinders, such as CO2, Argon, and Mix cylinders, to your existing aquarium fish CO2 tank regulator. Made of high-quality aluminum material, it is sturdy, durable, and built for long service life. Compact and lightweight, it is easy to carry and store, offering convenient use. It connects to M10 gas cylinder for opening and closing the gas. Specification: - Item type: CO2 cylinder adapter - Model: M10X1 to W21.8-14 (DIN477) Note: The W21.8-14 interface is only suitable for Europe, South Korea, Australia, and New Zealand. Material: Aluminum Color: Silver Package Contents: 1 x CO2 Cylinder Adapter Only the above package content is included; other products are not part of this sale. Note: Light reflection and different displays may cause the color of the item in the picture to appear slightly different from the real thing. The measurement allowed error is +/- 1-3cm.