How do I unlock a Panasonic SABTT400 blu ray dvd player

SOURCE: Region Code Unlocking for the Panasonic DMP-BD30K 1080p Blu-Ray Disc Player

how do I unlock my blu ray with factory remote?

SOURCE: LG Blu-Ray BD-370 unlock codes

http://www.multi-region.net/lg_5931

SOURCE: How can I unlock my panasonic dmp-bd80 blu ray

To return to the factory preset
(No setting)
≥Reset the unit as follows:
1 Press [POWER í/I] on the unit to turn off the unit.
2 Press and hold [;], [POWER í/I] and [< OPEN/CLOSE] on the unit at the
same time for more than 5 seconds until “HELLO” is displayed on the unit.
3 The power will turn on and then turn off.

SOURCE: unlock sony blu-ray bdp-s370 player

Turn on the BD player. Press and hold the PLAY button and the STOP button until UNLOCKED appears on the front panel display.

SOURCE: how to unlock dvd from

I believe this model is already Region Free out fo the box. What does it show on the back?