Features: Specially designed replacement for K303C CO2 regulator, fiting well with it. Can display real-time air output, backflow-proof design, preventing water from flowing back to the bottle. Bubble counter can be added infinitely to the regulator, meeting your high demands. Made from high-quality aluminum alloy and glass, has long-lasting durability and dependability. Specifications£º Color: Silver and transparent Material: Aluminum alloy & glass Note: Only 1 bubble counter is included. Package List£º 1 * Bubble Counter