A seat includes a base having {TAIL ~ a block} extended rearward for forming a pair of {HEAD ~ notches} 
A seat includes a base having { TAIL ~ a block } extended rearward for forming a pair of { HEAD ~ notches }
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD