See the dcu11 cable comes with a semisquare box in between - mainly used for user level functions of sony eric phones.
This cable can be used for unlocking and flashing.
GRIFFIN- it has different config since the box interface is already READY.
Twister-UFS - An intelligent mod made. It uses usb emulation.
NOW how u can use DCU11 for unlocking? U ll have to modify the cable.
visit this link
DCU-11 modification for FLASH / UNLOCK
very much detailed guide.
I m using it very comfortably. Use china made - u can cut the cost a little bit :P