US D298473 S
FIG. 1 is a top plan view of a filtration unit for exhaust air from a clean room helmet worn in a sterile environment or the like showing our new design;
FIG. 2 is a bottom plan view thereof;
FIG. 3 is a left side elevational view thereof, the right side being substantially similar in appearance;
FIG. 4 is a front elevational view thereof;
FIG. 5 is a rear elevational view thereof; and
FIG. 6 is a perspective view thereof.