Zero-torque putters, most notably pioneered by L.A.B. Golf with their "Lie Angle Balance" technology, are engineered to eliminate the natural twisting (torque) that occurs during a putting stroke.
While traditional putters often want to open or close depending on their weight distribution, a zero-torque putter is balanced to stay perfectly square to your arc throughout the entire motion. Think of it like power steering for your short game—by removing the need to manually "fight" the putter to keep the face square, you get a more consistent, repeatable stroke that stays on its intended line with much less effort.