D-NS921F

The D-NS921F is an S2 Sports model from 2004 built around durability and active use, supporting ATRAC3plus, ATRAC3, and MP3 playback with water resistance, strap-based handling, and a control layout built to stay usable during movement. G-Protection and long battery life helped it hold up in situations where most portable CD players would feel too exposed.

That gives it a very different personality from the rest of the lineup. The D-NS921F is part of the shrinking part of the category that still treated the disc player as something meant to be moved around with instead of used carefully indoors.