This tray 15 comprises a well 45 for holding markers and the like, and upstanding therefrom a pair of spaced apart flanges 46 and 47 dimensioned for entry into {HEAD ~ the channel} 41 of {TAIL ~ the extrusion} 37 
of
This tray 15 comprises a well 45 for holding markers and the like , and upstanding therefrom a pair of spaced apart flanges 46 and 47 dimensioned for entry into { HEAD ~ the channel } 41 of { TAIL ~ the extrusion } 37
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 HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH