I am no cattle expert by any means however I did put one of these up with the ties that dangle down about two weeks ago. It is amazing how well they work with a couple gallons of diesel and a couple ounces of pyrethrum (sp?). Fly problem immediately almost disappeared. I hung a 10ft + a 5 ft together across a 16 ft lane to a waterer. Not sure if this is what you were looking for but they seem to work well. The cattle had no problem going under them the first time.

Jim at Dawn

http://www.phwhite.com/