Schurr Einbau Wabbler
This is a Schurr Einbau Wabbler, which was designed to fit the ETM-9 keyer to replace the original paddles. I got this key from VK6VZ and then found that it fit perfectly onto an American Morse Equipment steel base.
I use this as my key with my secondary station kit that is left in the UK while I am working overseas.