What's the noun for couples? Here's the word you're looking for.
couple
Two of the same kind connected or considered together.
(informal) A small number.
One of the pairs of plates of two metals which compose a voltaic battery, called a voltaic couple or galvanic couple.
(physics) Two forces that are equal in magnitude but opposite in direction (and acting along parallel lines), thus creating the turning effect of a torque or moment.