a ring shaped pan having the vents about a perimeter edge of the pan positioned about the large open end of the recessed can, the vents for allowing {HEAD ~ the incoming air} to pass into the housing through {TAIL ~ the motor run blower} 
to pass through
a ring shaped pan having the vents about a perimeter edge of the pan positioned about the large open end of the recessed can , the vents for allowing { HEAD ~ the incoming air } to pass into the housing through { TAIL ~ the motor run blower }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL