The NS4158 is an Audio Power Operational Amplifier (Op-Amp) manufactured by Nsiway. It is a SOIC-8 type package that has been RoHS compliant, meaning that it is free from hazardous materials such as lead, mercury, and cadmium. It is ideal for use in audio power applications such as speaker amplifiers, preamplifiers, and headphone amplifiers. With a gain of greater than 29 dB and a power dissipation of 1.1 W, the NS4158 is an ideal solution for systems requiring a high level of performance. It is also very low cost with a single unit price of only $0.12.