Motorcycle helmets with a built-in mounting mechanism for installing a motorcycle intercom system, and parts and accessories thereof; motorcycle helmets with a built-in mounting mechanism for installing intercommunication apparatus in the nature of wireless communication devices for voice, data or image transmission, and parts and accessories thereof; motorcycle helmets with a built-in mounting mechanism for installing navigational apparatus for vehicles, and parts and accessories thereof; motorcycle helmets with a built-in mounting mechanism for installing wireless headsets for smartphones, and parts and accessories thereof; motorcycle helmets with a built-in mounting mechanism for installing cameras, camcorders and webcams, and parts and accessories thereof; motorcycle helmets with a built-in mounting mechanism for installing one or more dashboard cameras, and parts and accessories thereof; motorcycle helmets and their parts and accessories; automotive helmets and their parts and accessories; protective helmets and their parts and accessories; measuring and testing machines and instruments; acceleration sensors; accelerometers; automatic indicators of low pressure in vehicle tires; distance recording apparatus; distance measuring apparatus; gauges; gyroscopes; infrared sensors; kilometer recorders for vehicles; odometers; optical position sensors; speed indicators; temperature indicators; motion sensors; motion detectors; vibration meters; motorcycle helmet attachments adapted for intercommunication apparatus; motorcycle helmet mount bases adapted for intercommunication apparatus; motorcycle helmet attachments adapted for navigational apparatus for vehicles; motorcycle helmet mount bases adapted for navigational apparatus for vehicles; motorcycle helmet attachments adapted for wireless headsets for smartphones; motorcycle helmet mount bases adapted for wireless headsets for smartphones; motorcycle helmet attachments adapted for cameras, camcorders and webcams; motorcycle helmet mount bases adapted for cameras, camcorders and webcams; motorcycle helmet attachments adapted for dashboard cameras; motorcycle helmet mount bases adapted for dashboard cameras; audio speakers for automobiles; communications headsets; electronic apparatus for wireless reception, storage and transmission of data and messages; digital music players; Global Positioning System (GPS) apparatus; head-mounted video displays; headphones; headsets; helmet mounted digital cameras; helmet communications systems and their parts and fittings; holders to secure wireless communication devices to motorcycle helmets; holders to secure intercom devices to motorcycle helmets; intercommunication apparatus; intercoms; microphones for telecommunication; motorcycle helmet communications headsets using wireless telecommunication protocols; motorcycle helmet communications intercoms; motorcycle helmets integrated with a wireless headset for wireless communication; mounting brackets for attaching wireless communication devices to motorcycle helmets; mounting brackets for attaching intercom devices to motorcycle helmets; navigation apparatus for vehicles [on-board computers]; radar apparatus; radar detectors; rearview cameras for vehicles; remote control apparatus; remote control apparatus for the opening and closing of vehicle doors; remote controls for operating vehicle alarms; telecommunication machines and apparatus; vehicle radios; video recorders for automobiles; wearable video display monitors; wireless communication machines and apparatus; wireless speakers; parts and accessories for telecommunication machines and apparatus; personal digital assistants; smartphones; mobile computers; wireless headsets for smartphones; card reading equipment; cases adapted for computers; cases for smartphones; computers; computer peripherals; computer peripheral equipment; computer software; covers for laptops; covers for smartphones; covers for tablet computers; data processing apparatus; data processing equipment; discharge tubes, electric, other than for lighting; electronic integrated circuits; electron tubes; encoding and decoding apparatus and instruments; memories for data processing equipment; printed circuits; printed circuit boards; protective cases for tablet computers; protective cases for personal digital assistants; rectifier tubes; semi-conductors; thermionic tubes; thermionic valves; ultrasonic object detectors for use on vehicles; motorcycle racing helmets and their parts and accessories; automobile racing helmets and their parts and accessories; protective helmets for sports and their parts and accessories