This is a restored air conditioning compressor clutch and dual-sheave pulley assembly. The original engineering number is C9OA-2981-E, but it's not marked on the assembly. The original Ford service part number is C9OZ-2884-B (Motorcraft number YB-34). It's correct for the following applications:
The clutch and pulley assembly requires a C9AZ-2987-A field coil.