Shopping Bags (4PCS)PRODUCT DETAILS This Shopping Bags work by first spreading out the reusable bags and then letting the extended rails rest on any supermarket cart. This gives you a series of open and upright bags allowing you to pack your goods into color coded bags depending on the category of grocery that you are looking for. Detach one bag at a time to load into your car to transport home. After unloading all groceries, simply reattach the velcro and tightly wrap