Hammond's 140 EX Series Studio Grade Impedance Matching Audio Transformers operate in the 20 Hz to 20 KHz range. The metal can provides excellent shielding from a broad range of external sources. They are designed for maximum bandwidth and the lowest distortion at +10 dbm power level or less. The nickel core provides high permeability combined with low losses. Typical applications for these audio transformers include input/output isolation, line matching, driver, and hybrid applications.