Gatlin Manufacturing adds direct materials at the beginning of the production process, while conversion costs are incurred uniformly throughout the process. At the end of the period, equivalent units for direct materials were 250 more than equivalent units for conversion costs. 1,000 units were started during the period, and 1,000 units were also completed. Ending Work in Process Inventory was 50% complete. How many physical units were in ending Work in Process Inventory?