HEAVY DUTY double looped ends are two coils of the spring that connect to the eye-bolt and the pulley. This provide a sturdy replacement than single loops in the market. "ELECTROPHORESIS black coating with min 16,000 cycles. Never need to lubricate the spring and keep you hands clean." "AVAILABLE in color coded 90lb, 100lb, 110lb, 120lb, 130lb, 140lb, 150lb, 160lb, 170lb, and 180lb weight capacity to fit most 7ft hight door." "ORDERING - Please know the height and weight of your garage door before ordering. Extension spring are color coded, but the color repeat every hundred pounds. Tip : Use a analog scale and place in center of the garage door. Release the extension spring and record the weight on the scale." "SAFETY cable with the extra length of 144"" x 1/8"" 7x7 strand to avoid any spring to fly all over and during and after installation. The safety spring include 2 pcs S hook and 2 pcs three-eye splint." HEAVY DUTY double looped ends are two coils of the spring that connect to the eye-bolt and the pulley. This provide a sturdy replacement than single loops in the market.