{HEAD ~ first and second side portions} integral with {TAIL ~ each slotted portion} at one side edge of said slotted portions 
{ HEAD ~ first and second side portions } integral with { TAIL ~ each slotted portion } at one side edge of said slotted portions
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH