Aquarium CO2 One-Way Solenoid Valve Aquarium CO2 Solenoid Valve,DC 12V CO2 System Regulator for Fish Tank Inner Dia 4mm Outer Dia 6mm Gas Pipe Connect Bubble Counter One End Is Connected to 4mm Inner Diameter, 6mm Outer Diameter Gas Pipe, the Other End Is Connected to M10x1 External Thread Or Fine-tuning Valve, Bubble Counter Its on amazon for 18.99
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