BAR & GAUGE BRASS W/INSULATING HANDLE
The classic brass Bar & Gauge apparatus to prove and demonstrate the effects of heating a metal. If the bar is heated or if the gauge is chilled in ice, the bar cannot fit the gauge both in length and in diameter. Unlike the Ball & Ring, the two are not chained together.
The IEC item is carefully machined and matched for size so that the experiment works.
Many imported items are poorly made and have no chance of working.