This is a suspension castle nut as applied to various Fiat and Lancia cars.
Fiat X1/9 / Lancia Scorpion - Secures rear toe link assembly
Fiat 850 - Secures rear stub axle bearings and also front control arm cross-pin
Condition: OE/ RECONDITONED
Either an Original Equipment New Old Stock item, or a factory OE item recently stripped and replated in yellow zinc.