ArborMAX HRC ring bound loop prusiks are a popular friction hitch for lanyards, friction savers and anchors. This prusik has an ISC 28mm aluminum ring sewn in place, which is used for adjustment. Teufelberger HRC ThermaShield is a popular friction hitch cord for professional arborists. HRC (Heat Resistant Cord) ThermaShield is constructed of a spun Technora/Nomex cover, with a Vectran core. The Technora/Nomex cover is very heat resistant. Combined with the high strength, low stretch Vectran core, HRC offers a long wearing, fuzzy gripping professional hitch cord. 8mm HRC ThermaShield works best with 7/16" (11mm - 11.7mm) climbing rope. Made in the USA.