https://www.easel.ly/browserEasel/14621076">https://www.easel.ly/browserEasel/14621076. A quality roof will have them installed around the edge of the roofline, where vertical walls meet the roofing system incline, https://jemimawlhq924220.mybjjblog.com/more-about-stay-dry-roofing-51669805