Normally, any intentional radio transmission requires an FCC license pursuant to Title III. However, in recent decades the FCC has also opened some spectrum bands for unlicensed operations, typically restricting them to low power levels conducive to short-range applications. This has facilitated the development of a very wide range of common technologies from wireless garage door openers, cordless phones, and baby monitors to Wi-Fi and Bluetooth among others. However, unlicensed devices — like most radio transmission equipment — must still receive technical approval from the FCC before being sold into the marketplace, including to ensure that such devices cannot be modified by end users to increase transmit power above FCC limits.