Our quality vacuum bell jar demo is a great tool to discover how sound requires a medium to travel through. Remove the air from the jar and the sound from the bell gradually fades. The demo includes a glass bell jar, vacuum base plate, gasket, hose, and battery-operated ringer electric bell.

Technical Specifications:

• Vacuum Pressure for Bell Jar: <=-0.06MPa
• Electrical: 3V DC
• Temperature: 14 to 104°F (-10 to 40°C)
• Humidity: 85% Max
• Bell Jar: 6.5" x 9.75"
• Base: 8" x 1.5" 

*Requires 2 AA batteries and a vacuum pump - NOT INCLUDED*