This general-duty 12-1/4" x 3-3/8" replacement brake drum is specifically designed for Dexter 10,000-pound general duty axles. For proper fitment, the drum must have '9-123' stamped into it, making it compatible with trailer axles manufactured after 2009. This drum component features a robust cast construction with a precision-machined interior surface for optimal braking performance. The 3-3/8" brake width specification is critical - only brakes of this exact width will properly fit this drum. This replacement part maintains the original equipment specifications, ensuring reliable braking performance for your trailer applications. When installing, always verify the stamped numbers match your existing drum to guarantee proper fit and function.