The following items needed.
(1) Passport.
(2) Original and translated (certified/government acceptable) emergency document.
(3) Receipt of I-140 and I-485.
(4) Approval of I-140 (if you have).
(5) Air ticket (if you have).
If your AP case can be transferred from Service Center, you will not be asked the following items. If not, you have to bring the following items also.
(6) currently filled I-131,
(7) photos (2),
(8) I-131 application fee (check or cash).