The Emerson 24A34-6 Electric Heat Sequencer with 4 Switches is a controller designed for central furnaces. It operates at a voltage of 24V and is compatible with Emerson brand products.
I have used several of these units and have found them to have very consistent timing characteristics.
They have ample connections for any auxiliary loads, plus the pre-installed jumpers on the 24v. coil
connections are very convenient, allowing for quick and easy wiring in most situations. These jumpers
can also be easily cut off, allowing this device to be used in special circumstances. Overall, these
sequencers have proven themselves to be very reliable and an excellent value.