I just ordered a Fisher F4 & before I was using a Tesoro Cibola. I have emailed Fisher a few times and have not yet received a reply from them. Went to their site to download the manual for the F4 and says available April 2007, here it is May and still no online manual. Makes one wonder how Fisher would be if one really needs them for repair or something important. On the Tesoro forums it is not uncommon at all for some of the workers at the factory jump in & answer a question or reply with a tip or whatever. If you send them a email they always respond in a timely manner. Steve.