Gents: So far, I have come across this model sold by Mouser. I can get them for $11 each if I buy 10. 5 will replace the set in the 3K which are 26 years old, and other 5 will be spares. http://www.mouser.com/Search/ProductDetail.aspx?R=L100J20KEvirtualkey58810000virtualkey588-L100J20KE Comments pro and con please? Don N8ECH