PRUSIK CORD Prusik cords with the same high quality and long wear design as Access Rescue Ropes. Size selection should be based upon diameter of main line. Because of Rescue Technology's ability to manufacture a flexible cord that is both strong and highly resistant to abrasion, only one style of small diameter cord is produced. 100% nylon. Diameter: 6mm Strength: 1,700 lbf. Colors: Blue Mix, Red, Black Solid Spool Length: 300 ft. Use w/ main line: 3/8" - 1/2"