• Medline's Incentive Spirometers make it easy for patients and staff alike. • One-way valve ensures patients inhale rather than exhale into the unit. • Highly visible pistons and universal graphics (indicating correct inspiratory flow rate). • Other features include an oxygen connector for supplemental oxygen, convenient handle, flexible popple tubing and bedrail holder. • Available in 2,500 and 4,000 ml capacities.