Hex Key Wrenches, also known as an Allen wrench/key, is a shaft with 6 sides of the same diameter on each side. This allows it to be used with both ends. Forming an elbow, it is given the shape of an "L". But the Allen Key can also have a "Y", "S" or "T" shape. However, the "L" shape offers the advantage of creating a lever arm that can lean differently, depending on whether the long or short stem is used. This makes a hex key set perfect for use in tight spaces. They are also applied in cycling, where bicycles, frames, brakes, or gear-shifting systems.