The ornamental design for a convertiblestroller, as shown and described.
FIG. 1 is a front elevational view of a convertible stroller in a pull-behind configuration showing our new design.
FIG. 2 is a back elevational view of the convertible stroller in a pull-behind configuration.
FIG. 3 is a left side elevational view of the convertible stroller in a pull-behind configuration; the right side elevational view is a mirror image of the left side elevational view.
FIG. 4 is a top elevational view of the convertible stroller in a pull-behind configuration.
FIG. 5 is a bottom elevational view of the convertible stroller in a pull-behind configuration.
FIG. 6 is a left side perspective view of the convertible stroller in a pull-behind configuration.
FIG. 7 is a left side perspective view of the convertible stroller in a pull-behind configuration.
FIG. 8 is a front elevational view of the convertible stroller in a push configuration.
FIG. 9 is a back elevational view of the convertible stroller in a push configuration.
FIG. 10 is a left side elevational view of the convertible stroller in a push configuration; the right side elevational view is a mirror image of the left side elevational view.
FIG. 11 is a top elevational view of the convertible stroller in a push configuration.
FIG. 12 is a bottom elevational view of the convertible stroller in a push configuration.
FIG. 13 is a left side perspective view of the convertible stroller in a push configuration; and,
FIG. 14 is a left side perspective view of the convertible stroller in a push configuration.
The broken line showing is included for the purpose of illustrating unclaimed subject matter and forms no part of the claimed design.