The ornamental design for a singleloadingenhancementdevice, as shown.
FIG. 1 is a perspective view of a single loading enhancement device according to the present invention.
FIG. 2 is a perspective view of a single loading enhancement device according to the present invention; and,
FIG. 3 is a rear view of a single loading enhancement device according to the present invention.
The broken line showing of parts of the drawings is included for the purpose of illustrating use and environment and forms no part of the claimed design.