This above photo reveals my 2008 season design. It differs from my 2007 design in that the portal itself contains the complete treatment--standoffs and mono-line. Having the entire treatment attached to the portal simplifies in-field treatment addition, replacement or removal.

The mono-line (fishing line) is a clear blue line rated at 12 lbs (ideally the line is invisible as possible). The standoffs are formed from 16 gauge anchor wire. Specifics of this design are provided with the photos that follow. Note that this design (mono-line 3) is not suitable for front opening boxes where the front is hinged at the top--the wire standoffs of the treated portal will contact the box's top, and inhibit the opening of the front. However, my 2007 design (mono-line 2) will work with all boxes including front opening boxes where the front is hinged at the top, but it is more involved to install.