IPad2
From Droam Prepaid SIM Encyclopedia
You could download apple´s own "iPhone Configuration Utility" and make /edit your own APN profile and move It to your iPad or take the easy road.
The easy road Is to do this:
1. Open apn.droam.com from Ipad using WIFI connection
2. Choose Custom APN
3. Save it on the Ipad
4. Install It.