DINEX OneBox Diesel Particulate Filter Assembly for Detroit Diesel Engines (Air Assisted, EPA10). This full OneBox aftertreatment assembly addresses the operational challenge of managing particulate emissions and prolonged downtime associated with aging or damaged exhaust treatment modules on heavy‐duty Detroit Diesel powertrains. Designed as a factory‐style replacement for air‐assisted OneBox systems, the assembly enables fleets to restore certified emissions control functionality while streamlining installation and service workflows. The OneBox approach consolidates multiple aftertreatment stages into a single modular housing to reduce component count and simplify removal and replacement during scheduled service or failure recovery. Including required hardware such as clamps and gaskets, the assembly reduces time spent sourcing separate parts and shortens out‐of‐service intervals compared with piecemeal repairs. Specified for EPA10 applications and sized for common Freightliner/Western Star installations, the unit is engineered to fit the OEM mounting envelope and service interfaces used on Detroit DD13/DD15 platforms, supporting regulatory compliance goals without extensive chassis modification. Measurable operational value includes reduced mean time to repair through one‐piece replacement, predictable parts interchangeability for faster stocking strategies, and a consolidated repair path that lowers shop labor hours per aftertreatment failure. Physical attributes relevant to planning and logistics include the assembly’s published overall dimensions and weight for lift, transport, and storage considerations. When paired with correct DPF cores and recommended sensors or mechatronics, the OneBox restores exhaust treatment capacity and enables return to service with EPA10 particulate control performance met. This assembly is intended for technicians and parts managers who require a purpose‐built aftertreatment replacement that minimizes installation complexity, reduces downtime, and supports measurable fleet emissions compliance targets.