Examples of binding posts used during the 19th century are telegraph key and blasting machine devices.
During the late 1940s, General Radio created a new binding post that had a jack in a cap.
[1][2][3] Today it is commonly known as a "five-way" or "universal" binding post, which allows many types of connection methods: Even so-called isolated binding posts are typically not sufficiently isolated to protect users from coming into contact with their metal parts carrying voltage.
On several types of equipment it has been becoming common to no longer use the traditional binding posts, but safety banana jacks.
In order to permit the use of double banana plugs, the most common distance between the centers of the plugs should be 3⁄4 inch (19 mm), which originated on General Radio test equipment during the 1920s, however 3⁄4 inch is not the only spacing.