Family Radio Service (FRS), PMR446 and other consumer-grade "bubble pack" radios often include a feature called "Interference Eliminator Codes", "sub-channels", or "privacy codes"—the latter two being especially misleading as, contrary to what sales literature may say, they do not afford privacy or security, but serve only to reduce annoying interference by other users or other noise sources; a receiver with the tone squelch turned off (e.g., frequently done by selecting code "0") will hear everything on the channel. GMRS/FRS radios offering CTCSS codes typically provide a choice of 38 tones, but the tone number and the tone frequencies used may vary from one manufacturer to another (or even within product lines of one manufacturer) and should not be assumed to be consistent (i.e. "Tone 12" in one set of radios may not be "Tone 12" in another). When a radio offers more than 50 codes (121 is becoming common), the higher ones (e.g. 39-121) are usually DCS codes.