The Kubota 6870921700 undercarriage is a genuine OEM replacement part designed for various Kubota KX and U series compact excavators. This essential component provides the structural foundation for the machine's tracks and supports the upper structure, ensuring stable operation and durability in demanding conditions. It is a direct fit for models including KX040-4, KX121-3, KX121-3S, KX121-3ST, KX161-3, KX161-3S, KX161-3ST, U35, U35-S, U35-S2, U45, U45S, and U45ST.