Shop Singing Rock Route 44 10.5mm Static NFPA. Route 44 technology developed exclusively by Singing Rock. This unique sheath-braiding technology proves there is a better way to make a rope. Route 44 is the only rope in the world to use this patented technique making the rope more perfectly round and giving the sheath a perfect blend of thickness, durability and handling characteristics. Recommended use: rescue operations, work positioning, military and police use, caving, fixed rope for expeditions, and big wall.