Other Features
In terms of additional features, the NIU C21A includes a stereo FM radio, allowing users to listen to music and news on the go. However, the absence of a 3.5mm audio jack necessitates the use of an external adapter for wired audio connections. The phone supports simple SMS and IM for messaging but does not support multimedia messaging or Java-based applications. The lack of games and relatively few built-in features is consistent with the phone's emphasis on essential functionality.