An impact wrench (also known as an impactor, air wrench, air gun, rattle gun, torque gun, windy gun) is a socket wrenchpower tool designed to deliver high torque output with minimal exertion by the user, by storing energy in a rotating mass, then delivering it suddenly to the output shaft.
In mathematics, especially in set theory, a setA is a subset of a set B, or equivalently B is a superset of A, if A is "contained" inside B, that is, all elements of A are also elements of B. A and B may coincide. The relationship of one set being a subset of another is called inclusion or sometimes containment.
