FIG. 1 is a rear and bottom perspective view of an inhaler; FIG. 2 is a bottom plan view of an inhaler shown in FIG. 1; FIG. 3 is a top plan view thereof; FIG. 4 is a left side elevational view thereof; FIG. 5 is a right side elevational view thereof; FIG. 6 is a rear elevational view thereof; and, FIG. 7 is a front elevational view. The broken line showing is for illustrative purposes only and forms no part of the claimed design.