1/4" Shock Cord #SC-2 (1/4in X 18in) (Shock Cord)

Dimensions from the 1974 Estes Custom Parts Catalog.

Earl's kit's part was measured at 18.25" long.
Length: 18.25 inches
Material: Rubber cord (flat 6 mm, 1/4 in) (4.3 g/m)

Designs: