The Lionel 1053 Transformer was available from 1956 until 1960. It generated 60 Watts of power and would control one train. It does have a built-in circuit breaker. See No. 91 Circuit Breaker for more information about circuit breakers in transformers issued between 1957 and 1960. It came with a horn/whistle control button. The "X" printed on the box illustrated above indicates that this transformer was originally included in a set.