On {TAIL ~ the outer peripheral edge} of the flange 11a are formed {HEAD ~ an engaging edge 11e} and a cutout 11g 
On are formed
On { TAIL ~ the outer peripheral edge } of the flange 11a are formed { HEAD ~ an engaging edge 11e } and a cutout 11 g
REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH REL REL HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH