Hello, and thank you for using this service. I'll be helping you with your problem today.It's a bit hard to describe, but the center gasket insert should actually overlap the left and right end of the door gasket. The round part of the gasket should touch the floor when you shut the door, so if I understand your terminalogy correctly, the "c" shape should go lips down with the door open. Below is a picture of how you should position the gasket when you're installing it if you're standing in front of the door.Please remember to rate my service once you have all the information you need. If you have any other questions, please ask me – I’ll be happy to respond. Thank you!