David and Tom,
Sorry guys. Looks like I forgot the link in my post. Bernie had it correct. It’s http://www.bmumford.com/ and the following link will take you to the accessories page which has the sensors. If you scroll down you’ll also find a ‘hairspring sensor’ for those who may have an urge to vibrate hairsprings. http://www.bmumford.com/mset/access/access.html
David, I see what you mean. At first glance it does look like bumford! 
Enjoy
Bob
