125BSE by Hammond Manufacturing is a audio transformers / signal transformers designed for reliable performance in electronic applications. It is widely used in industrial, automotive, and power management systems.

Transformer products are arrays of magnetically-coupled inductors in which the characteristic of the individual inductors within the array are typically non-uniform. They are most commonly used for either or both of two purposes; the conversion of AC power or signals between substantially different voltage levels, or the transmission of the same across the insulation barrier between two galvanically isolated circuits.