Comparison : Item # 1240 A, High Voltage Isolation Transformers, Model SI-1240 A
Item # 6477, High Voltage Isolation Transformers, Model SI-6477
Item # 2971, High Voltage Isolation Transformers, Model SI-2971
Item # 1483, High Voltage Isolation Transformers, Model SI-1483
Item # 5809, High Voltage Isolation Transformers, Model SI-5809