It says that it's ds lite compatible and that's what I'm trying to put it in but it doesn't want to go in. It's facing the correct way. I tried to apply force but it doesn't go in. My ds browser expansion pak fits just fine and is the same size as the ez flash 3in1. Nevermind, I got it in. I had to hold the ds by the sides with my thumbs and then push it in with my two index fingers. Strange..