AD821 dual silicon matched PNP transistor. AKA : a differential amplifier transistor. Package: 6-TO-71 Status: SNOS (Super rare NOS) in perfect condition. Date code: 7619 ** Note this is being offered to the serious synth builders,who want the real thing, with no messing about, no compromise.** This is the first one in 10 years to come available. This device now nearly 50 years old. Tested: YES hFE gain : 164 / 166 (150~800 stated as in spec') RoHS compliant: No