Polyform HTM-1 Fender 6.3" x 15.5" - Blue [HTM-1 BLUEWO]HTM 1 Fender 6. 3" x 15. 5" Blue In keeping with the Polyform tradition of quality, the HTM (hole through middle) boat fender was designed to provide maximum protection in a wide variety of applications. Vertical ribs for extra protection, reinforced tube ends to prevent lines from pulling through if the fender gets caught in a tight spot, and extra wall thickness to resist punctures and tears are just a few of the features of this high quality fender