These carriers are optional. They are placed in the tray under the grass, with the ribbon like handles sticking out the front and back. Tuck the handles underneath the plastic.
When it comes time to change the sod, just pull the handles out. Take a utility knife with a razor blade, cut the grass sod directly in half, and you can move the sod in two separate pieces. It is half the weight and you do not have to get your hand dirty after your pet has done his business on it.
The carrier has handles and is used to carry sod from home-to-trash or new sod from store-to-home.