I don't know for sure

I just know you can get them on e-bay, or the USMLE forum. I got mine from Kaplan. They are the best.

Kaplan.com

http://www.kaptest.com/repository/templates/Lev3InitDroplet.jhtml;jsessionid=YQSUZ5PRVEBXLLA3AQJHBNVMDUCBG2HB?_lev3Parent=/www/KapTest/docs/repository/content/Medical_Licensing/Medical_Home&source=med_home