The filter body is rotatable around {HEAD ~ the axle}, which is permeable to {TAIL ~ the x ray radiation} 
The filter body is rotatable around { HEAD ~ the axle } , which is permeable to { TAIL ~ the x ray radiation }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL