The Terra System is Croakies newest retainer. We have taken our classic Terra Cords, and added the interchangeable end technology of the ARC family. The Terra System features the same durable Terra climbing rope, with length and adjustment options, color options and six end options. Our XXL Terra & XL Tite Ends fit big bulky frames, the XL Terra fit large frames, the REG Terra & Tite Ends fit medium to small frames, and the Micro Terra fit small frames. Match the fit to your glasses and move on.