it's got a patent# on the site: 6,005,950 look this up online, and see what's in it. http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1='6005950'.WKU.&OS=PN/6005950&RS=PN/6005950 (that's a long url, careful when you cut & paste) andy