how to create Transfer requirement with storage unit type ( SUT )

Hi ,

I meet a serious problem,in the storage type 030 there has two SUT (L,box).When i creat a transfer requirement from storage type 030 to 150 by PK23. It always automatically create TO with SUT 'L',but i want TO with box every time.And i found the TR's item has SUT information,but i don't know how to input it because of it couldn't input.

I think if the TR with SUT 'box',the automatically create TO will be right.