This is a used boom assembly designed to fit CAT 345 B, C, and D excavator models. The boom is a critical component that extends from the excavator's main body and supports the digging bucket, allowing for extended reach and depth when excavating. At $8,500, this used part offers a cost-effective replacement or repair option for equipment owners needing to restore or upgrade their excavator's digging capability. Being a wear item on heavy machinery, replacing a damaged or worn boom can significantly improve the machine's performance and operational lifespan.