Not aware of anyone making 20ga extensions or wire. Usually available in 22ga and 24ga. I believe I am the only company currently offering [link=http://www.dreamworksrc.com/catalog/index.php?cPath=3]18ga[/link] silicone jacket extensions. Not sure what your application is but we have used up to 60" leads with no need for RF Fliters. The filters, or chokes as they are sometimes called, are used to block stray RF from finding it's way to the rx. Long leads can act as an antenna collecting unwanted signals...