The Safe T Climb extension ladder anti-fall device is the only safe way to ensure proper ladder angle and to prevent the kick-out or slipping of the ladder. Made out of Heavy-Duty 16 gauge steel but only weighs 8 lbs. Attaches to all extension ladders (wood, aluminum or fiberglass). All duty rating (Type III, II, I, IA and IAA). Works on all types of roofs (wood, tile, composition, rock and parapet walls) and all roof pitches (when properly installed).