The ornamental design for a trailerunit, as shown and described.
FIG. 1 is a front perspective view of a trailer unit showing my new invention;
FIG. 2 is a front view of the trailer unit of FIG. 1.
FIG. 3 is a rear view of the trailer unit of FIG. 1.
FIG. 4 is a left side view of the trailer unit of FIG. 1.
FIG. 5 is a right side view of the trailer unit of FIG. 1.
FIG. 6 is a top view of the trailer unit of FIG. 1; and,
FIG. 7 is a bottom view of the trailer unit of FIG. 1.
The broken line showing of the environment is for illustrative purposes only and forms no part of the claimed design. The broken lines which define the boundaries of the claimed design form no part thereof.