Step Unit for Spa

FIG. 1 is an oblique view of a step unit for spa showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines in the drawings are included for the purpose of illustrating portions of the step unit for spa and form no part of the claimed design.