CO2 external diffuser for fish tank Features: Diffuser uniform, delicate! Metal material, strong and pressure ! Tower design + buckle fixed to prevent water pipe from falling off! Do not use wrench tools to disassemble the product, manually tighten and open it! Test before use, The best use effect of ceramic head: It is better to use it after 24 hours of immersion in aquarium! Use CO2 equipment to output CO2 into the filter and filter tube, and input CO2 into the fish tank, making aquatic plants healthier! Size: -16MM: Contact the internal diameter of 16mm water pipe installation (CO2 output using 4 x 6mm gas pipe) Color: silver Material: aluminum alloy Package Contents: 1 x aquarium carbon dioxide diffuser 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.