Final answer:
The question is looking for a specific product series brand name of a synthetic base stock gear oil that doesn't include PAO; without more information, the exact brand cannot be identified.
Step-by-step explanation:
The question refers to a specific product series brand name for a synthetic base stock gear oil product that does not contain PAO (Polyalphaolefin). Companies in the lubricant industry offer different product lines that may utilize various synthetic base stocks such as esters, Group III base oils, or other synthesized hydrocarbons for enhanced performance benefits in certain applications, as opposed to the use of conventional mineral oils. Since the exact brand name isn’t provided in the question, one cannot specify the brand without additional information. However, when selecting a synthetic gear oil, it's essential to consider the viscosity, additives, and the specific performance requirements of the machinery for optimal protection and efficiency.