a plurality of elongated, generally {HEAD ~ U} shaped clip members, each said clip member having a flat base, sidewalls extending outwardly from {TAIL ~ said base} at right angles to and on opposite sides of said base, each said sidewall terminating in an outer end portion inclining inwardly toward one another and having an inwardly facing ridge on an external surface of each said sidewall beneath said upper inclined end portion 
a plurality of elongated , generally { HEAD ~ U } shaped clip members , each said clip member having a flat base , sidewalls extending outwardly from { TAIL ~ said base } at right angles to and on opposite sides of said base , each said sidewall terminating in an outer end portion inclining inwardly toward one another and having an inwardly facing ridge on an external surface of each said sidewall beneath said upper inclined end portion
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH