HUD is short for Head Up Display, HUD is widely used in the aircraft’s fight aids. Pilots can get important information by HUD without looking down. HUD first appeared in military aircraft to decrease the frequency of pilot looking down to see the dashboard, because HUD can increase the safety, many air-crafts are equipped with HUD.Support BluetoothOnly available for AndroidV-checker H501 HUD can be used on All OBD standard vehicles.V-checker H501 HUD can be used on All OBD standard vehicles.