I claim the ornamental design for a promotional cap strap cover, as shown and described.
FIG. 1 is a top perspective view of the promotional cap strap cover of the subject invention mounted on the back strap of a cap, viewed from the inside of the cap;
FIG. 2 is a top view of the promotional cap strap cover depicted in FIG. 1, the bottom view being a mirror image thereof;
FIG. 3 is a rear view of the promotional cap strap cover of the subject invention mounted on the back strap of a cap;
FIG. 4 is a front view of the promotional cap strap cover of the subject invention mounted on the back strap of a cap, viewed from the inside of the cap;
FIG. 5 is a side end view of the promotional cap strap cover of the subject invention mounted on the back of a cap strap, the other side view being a mirror image thereof.
FIG. 6 is a top perspective view of the promotional cap strap cover of the subject invention, mounted on the back strap of a cap, taken from the rear of the cap.
The broken lines along the surfaces of the promotional cap strap cover depict environmental structure for the purpose of illustrating placement of promotional markings on the promotional cap strap cover and do not form part of the claimed design. The broken line outline of the cap illustrates the environment of the promotional cap strap cover and forms no part of the claimed design.