Compatible Model: Co2 Quick Adapter only replacement for Crystal 3.0 or Duo or Terra or Art or E-Duo or soda maker,can connect Co2 refill adapter Accessories,Co2 Cylinder with TR21-4 Male Thread. Easy to Install: The Co2 Quick adapter with split design, it is very convenient to install. It can be installed without removing the machine base. Comes with 3 replaceable rubber rings. Used to replace aging, dirty, damaged rubber rings. Please note:the physical slightly color difference or difference, does not affect the use, please do not mind! Colour:-Red Material:aluminum Package Contents: 1 x CO2 Quick Adapter 3 x replaceable rubber rings 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.