Ring terminal, 20 AWG, #6 stud
The 1577625-1 is a PIDG / Strato-Therm ring terminal from TE Connectivity AMP Connectors, terminated to 20 AWG wire with a #6 stud hole. The terminal is insulated with gray PEEK, carries a nickel-plated copper contact, and uses a serrated crimp barrel for wire grip.
