4 mm Ultrahigh Molecular Weight webbing w/ sewn-in fall indicator, Forged steel rebar hook, Steel carabiner, Steel O-ring.The Safewaze FS-FSP1409-W-RBH 9 ft Web retractable lifeline features a mobility enhancing swivel-top, rugged durable housing, and unique braking system that eases shock and minimizes free fall distance in theMaterial: Aluminum housing, 1 in 25.