Yes, the Ham II Control box can be used with the Ham M, Ham II, Ham III, Ham IV, and Tailtwister. And they are basically all the same control boxes!!!! 73 Mike K0BUD -- FAQ on WWW: http://www.contesting.com/towertalkfaq.html Submissions: towertalk@contesting.com Administrative requests: towertalk-REQUEST@contesting.com Problems: owner-towertalk@contesting.com Search: http://www.contesting.com/km9p/search.htm