I have drop windows on the head and will often need to keep them down due to heat.  Do the window screens attach to the bars that stay up, or do you have to attach some kind of rings around the parameter of the window on the inside of the trailer? 

Thanx.

Most of them attach to the perimeter of the window with rings.

My preference is the "slip on" screen available at this website >>>> http://www.trailerhitchboss.com/

They are  pricey but they don't tear loose and are wearing very well.

Thanks, Mr. Goff, for the nice comments about our screens.  We try our best to produce custom-made high quality horse trailer and trailer accessories that will last.  I hope you are enjoying your screens and will give us a call if we can help you with other horse trailer accessories.

Thanks so much

Rick