The Vibroplex is a popular brand of side-to-side mechanical, semi-automatic Morse key (also known as a bug) first manufactured in 1905 by the Vibroplex company.
The most common Vibroplex models have a single lever with a flat thumbpiece, or paddle, on the left side and a fingerpiece, or knob, on the right side.
When the knob is pressed from the right it makes a continuous contact suitable for sending dashes (or dahs, as most operators call them). When the paddle is pressed from the left, a horizontal pendulum at the opposite end of the lever is set into motion, intermittently closing a set of contacts, which sends a series of short pulses (dits) at a speed that is controlled by the position of the pendulum weight. A skilled operator can achieve sending speeds in excess of 40 words per minute with a bug.
The Vibroplex Company is currently owned by amateur radio operator Felton "Mitch" Mitchell, also known by the call sign W4OA. The Vibroplex Company has booths at the Orlando Hamcation, the Dayton Hamvention and the Huntsville Hamfest each year where it displays and demonstrates the many models of its telegraph keys, including the Original Bug. The Vibroplex Original Bug key has been in continuous production for over 100 years with only minor cosmetic changes.