The Square D QOB140 is a 40 A Miniature Circuit Breaker designed for use in electrical systems with a voltage rating of 120/240 Vac. This circuit breaker is a 1-pole model from Square D, a well-known brand in electrical equipment. With a current rating between 31-40A the QOB140 is suitable for protecting circuits from overloads and short circuits in various industrial and commercial settings.