Another slightly shorter formula is

=SUMPRODUCT(($A$26:$A$34=K$1)*(OR((LEFT($B$26:$B$3 4)={"4""5"})))*$D$26:$G$34)

where I guess you must change \ to , (comma). \ is because I use Danish settings.

Edit: {"4""5"} here I wrote {"4" backslash "5"} but it was changed when I posted. I think you should use {4,5}.