With the adapter, the Crystal glass carafe can also be used with the DUO sparkling water maker.

Instructions:
Place the adapter with the labeled side facing up in the bottle holder of the SodaStream DUO or E-DUO sparkling water maker. Then, place the SodaStream 0.7 L glass carafe on the adapter inside the bottle holder and carbonate the water as usual.

The adapter is exclusively designed for the use of the SodaStream 0.7 L glass carafe in the SodaStream DUO and E-DUO sparkling water makers. Improper insertion of the adapter may cause the glass carafe to overflow during carbonation or the bottle holder may not close properly. In some cases, the DUO or E-DUO sparkling water makers may be more prone to overflow while carbonating. To avoid this, press the carbonation button firmly down for about one second. Only press the carbonation button once after the sound of pressure release is audible.