There are versions that require 4 wires, and those that require only 3 wires, but they will both interchange. These are new, but since they're manufactured using an automated process, they are re-worked as necessary by hand and then tested 100%. 15$ core charge refunded when we receive your old (salvageable) timer. NO CORE RETURN FOR BORG TIMERS! CONTIGUOUS USA ONLY!
This is the timer circuit board located under the canopy cover as shown in this diagram: