Telegraph Key

A Telegraph Key, also called a CW Key, Morse Key, or simply Key, is the type of momentary switch used for sending Morse Code via CW.

Telegraph Keys, as par the name, were originally invented for landline telegraphy but morse code and thus the keys also saw use in early radio telegraphy, in the modern day, keys are available in straight, paddle, and iambic configurations. (There should be a chart of morse keys under this)