The first marking side 30 and the second marking side 31 are generally planar to accommodate unique marking indicia, such as barcodes,numbers, trademarks and the like that may be imprinted on the marking sides 30, 31 with devices such as lasers, inkjet printing, silk-screening, and the like.T slot frame 44 is carried by the head portion 11 adjacent the perimeter edge 34 and proximate the circumf