10PCS LM324N LM324 DIP-14 TI Low Power Quad Op-Amplifier IC – eElectronicParts
Amazon.com: Major Brands LM324N General Purpose Quad OP Amplifier, -16-32 Volt, 14-Pin, Plastic Dip Tube, 4.57 mm H x 6.35 mm W x 19.3 mm L (Pack of 20) : Industrial & Scientific