FIG. 1 is a top up, perspective view of a tandem sub, showing an embodiment of my new design;
FIG. 2 is a top down, perspective view of the tandem sub as shown in FIG. 1;
FIG. 3 is a bottom up, perspective view of the tandem sub as shown in FIG. 1;
FIG. 4 is a bottom down, perspective view of the tandem sub as shown in FIG. 1;
FIG. 5 is a bottom elevated view of the tandem sub as shown in FIG. 1;
FIG. 6 is a top elevated view of the tandem sub as shown in FIG. 1;
FIG. 7 is a left side elevated view of the tandem sub as shown in FIG. 1;
FIG. 8 is a right side elevated view of the tandem sub as shown in FIG. 1;
FIG. 9 is a front view of the tandem sub as shown in FIG. 1;
FIG. 10 is a rear view of the tandem sub as shown in FIG. 1;
FIG. 11 is a top up, perspective view of a tandem sub, showing an alternative embodiment of my new design;
FIG. 12 is a top down, perspective view of the tandem sub as shown in FIG. 11;
FIG. 13 is a bottom up, perspective view of the tandem sub as shown in FIG. 11;
FIG. 14 is a bottom down, perspective view of the tandem sub as shown in FIG. 11;
FIG. 15 is a bottom elevated view of the tandem sub as shown in FIG. 11;
FIG. 16 is a top elevated view of the tandem sub as shown in FIG. 11;
FIG. 17 is a left side elevated view of the tandem sub as shown in FIG. 11;
FIG. 18 is a right side elevated view of the tandem sub as shown in FIG. 11;
FIG. 19 is a front view of the tandem sub as shown in FIG. 11;
FIG. 20 is a rear view of the tandem sub as shown in FIG. 11;
FIG. 21 is a top up, perspective view of a tandem sub, showing an alternative embodiment of my new design;
FIG. 22 is a top down, perspective view of the tandem sub as shown in FIG. 21;
FIG. 23 is a bottom up, perspective view of the tandem sub as shown in FIG. 21;
FIG. 24 is a bottom down, perspective view of the tandem sub as shown in FIG. 21;
FIG. 25 is a bottom elevated view of the tandem sub as shown in FIG. 21;
FIG. 26 is a top elevated view of the tandem sub as shown in FIG. 21;
FIG. 27 is a left side elevated view of the tandem sub as shown in FIG. 21;
FIG. 28 is a right side elevated view of the tandem sub as shown in FIG. 21;
FIG. 29 is a front view of the tandem sub as shown in FIG. 21; and,
FIG. 30 is a rear view of the tandem sub as shown in FIG. 21.
The broken lines consisting of dashes show an environment that forms no part of the claimed design. The broken lines consisting of a double-dot/dash pattern show a boundary of the claimed design.