I don't know about off the hardware but I've had one on my roof for five years and the woodpeckers quit banging on my fireplace pipe. 73 Steve W8GAz -- 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