The product is Therm-O-Disc Heat Sequencer models B1256559 309837 H10-20 and C30-70. These central furnace heating system components are designed for use in home heating and cooling systems. The multicolor sequencers are specifically designed for furnaces and are reliable components for maintaining optimal heating efficiency in a home. The Therm-O-Disc brand ensures quality and durability in the heating and cooling systems of a central furnace.