After surgery or during prolonged rest, breathing exercises are performed several times a day, often without anyone to confirm that the inspiration is deep enough. The Salter Labs 4000 ml spirometer provides this benchmark. The piston rises in the graduated column according to the force of inspiration, and the volume reached can be read immediately.

• The transparent column shows the piston's position during inspiration, with nothing to manipulate
• The mouthpiece connected to a flexible tube can be brought to the mouth without changing position in bed or in a chair
• The lightweight case remains within reach on the bedside table between exercises