Briefcases are an essential component for those who routinely transport documents, files and electronic devices for business purposes. Hardside models, which are made from materials like polycarbonate, plastic ABS, polypropylene or aluminum, offer superior protection to interior contents, while softside varieties, made from fabrics like canvas, leather, polyester and nylon, are more flexible and supple. Various features, including top comfort-grip handles, a removable padded shoulder strap, wheels and a retractable handle, provide maximum versatility. Large interior compartments, lined with a fabric like velvet, suede or nylon, keep files and notes in order, while smaller chambers rein in things like a cell phone and business cards. Gold, brass or silver hardware elements with locking mechanisms keep confidential papers and expensive equipment safe and secure. Some briefcase models have a large flap that goes over the front of the case, while others simply open from the top. Briefcases with feet on the bottom help the bag stay clean and in an upright position.