what is the primary sector

I review Ryobi's first 18V brushless Hammer Drill with a whopping 750 in-lbs torque! I also compare it to similar hammer drills in it's class including the previous Ryobi 18V hammer drill to see how the new model stacks up. Ryobi 18V Brushless Hammer Drill P251 / P1813 Specs/Pricing/Warranty Ryobi 18V Brushless 1/2" Hammer Drill P251 / P1813 18V brushless motor...