in step {TAIL ~ the first cooktop unit} is preassembled with {HEAD ~ one cooking system type} and the second cooktop unit is preassembled with a different cooking system type prior to mounting on the base units 
in step { TAIL ~ the first cooktop unit } is preassembled with { HEAD ~ one cooking system type } and the second cooktop unit is preassembled with a different cooking system type prior to mounting on the base units
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH