what is the range of a key fob
Remote keyless system Keyless remotes contain a short-range radio transmitter, and must be within a certain range, usually 5–20 meters, of the car to work. When a button is pushed, it sends a coded signal by radio waves to a receiver unit in the car, which locks or unlocks the door. Most RKEs operate at a frequency of 315 MHz for North America-made cars and at 433.92 MHz for European, Japanese and Asian cars. Modern systems since the mid-1990s implement encryption as well as rotating entry codes to prevent car thieves from intercepting and spoofing the signal.[3] Earlier systems used infrared instead of radio signals to unlock the vehicle, such as systems found on Mercedes-Benz,[4] BMW[5] and other manufacturers.
Piano Most modern pianos have a row of 88 black and white keys, 52 white keys for the notes of the C major scale (C, D, E, F, G, A and B) and 36 shorter black keys, which are raised above the white keys, and set further back on the keyboard. This means that the piano can play 88 different pitches (or "notes"), going from the deepest bass range to the highest treble. The black keys are for the "accidentals" (F♯/G♭, G♯/A♭, A♯/B♭, C♯/D♭, and D♯/E♭), which are needed to play in all twelve keys. More rarely, some pianos have additional keys (which require additional strings). Most notes have three strings, except for the bass that graduates from one to two. The strings are sounded when keys are pressed or struck, and silenced by dampers when the hands are lifted from the keyboard. Although an acoustic piano has strings, it is usually classified as a percussion instrument rather than as a stringed instrument, because the strings are struck rather than plucked (as with a harpsichord or spinet); in the Hornbostel–Sachs system of instrument classification, pianos are considered chordophones. There are two main types of piano: the grand piano and the upright piano. The grand piano is used for Classical solos, chamber music, and art song, and it is often used in jazz and pop concerts. The upright piano, which is more compact, is the most popular type, as it is a better size for use in private homes for domestic music-making and practice.