Commercial intercommunications (intercom) systems vary in type and function. Because commercial establishments often house harsher environments (concrete walls, large expanses of space, more cabling to cause interference, etc.), commercial intercom systems are more robust than residential systems and proper installation is paramount. APT has supplied intercom solutions ranging from wired to wireless, two stations to five-hundred stations. Systems can operate hands-free or push-to-talk, depending on the application.