Description: 1. Patented 2-layer impellers, one clockwise rotating and one anticlockwise rotating enable to diffuse CO2 or O3 completely. 2. Leaking-proof lock design enables to be hang-on tank, submersed in aquarium or linked with a external filter. 3. Stylish device made of special, durable, acid and alkali resistant and toxic-release free plastics. 4. Innovative design is compatible with diverse tanks, internal or external use. Important notices: 1. In case of accumulated CO2 inside chamber due to excess intake CO2 and slow flow rate, it’s requested to release accumulated CO2 from chamber first then adjust CO2 inlet to proper intake amount. 2. Upright installation only.