Split CO2 Quick Adapter with 2 Spare Sealing Ring TR21 4 Thread for Duo CO2 Soda Water Machine pink.Feature: 1. Universal Compatibility: The CO2 quick adapter is compatible with soda makers like for DUO, for ART, for TERRA, and more. It fits standard 60L CO2 cylinders with TR21 4 threads, bridging old and new models. 2. Split Design Convenience: Featuring a split design, this CO2 quick connector allows for easy installation without removing the machine base. Comes with replaceable rubber rings f