Audio equipment includes landline telephones, stereos, radios, recorders, headphones, headsets, and accessories that allow hands-free communication in loud industrial areas. Two-way radios and accessories are real-time, push-to-talk voice communication tools that allow people to share information and alerts, collaborate, and coordinate action. Portable radios tune into AM, FM, and shortwave frequencies to play music and broadcast news and reports. Phones and accessories connect with landline service and are built to make and receive calls in specific environments like commercial and industrial areas. Marine stereo systems include parts, components, and speakers to build radios for use on boats, ships, or near marinas. Headphones and headsets allow hands-free communication in loud and noisy industrial and commercial areas. Digital voice recorders convert data recorded on cassette tapes into digital files that can be saved for playback or archived.