Value match (but not exact) like ctrl+F

Formula:

INDEX(polarspeed!$E:E,MATCH(main!A2,polarspeed!$A:A,0))

Include INDEX and MATCH with this bit:

Formula:

=IF(COUNTIF(A$2:A2,A2)>1,"Duplicate",IF(SUMPRODUCT(--(LEFT(polarspeed!$A$2:$A$8,7)+0=main!A2))>0

So it finds data by part of the value, tells me if its a duplicate