custo med GmbH supplied two models of 3 liter syringes to calibrate the custo spirometers.
In the past custo med supplied a blue syringe with a separate silicon adapter.
This adapter fits to all custo med spirometers
Currently custo med supplies a grey syringe with a built-on silicon adapter that is only suitable for the spirometers with the small mouth pieces
The large mouth piece from the older spirometers will pop out when you pump the air out of the 3 liter syringe.