I have recently received information from an associate whom has just returned from the 2008 ConExpo. During the Expo he was approached by several people enquiring as to the extruded plastic rebar support ( bar chairs ) he was he using in an exhibit. He was queried as to where he obtained these plastic rebar support ( bar chairs )as they had not seen anything similar in the States. If this is the case what method is employed to hold the rebar in position.