Apple has discontinued the iPod Nano and iPod Shuffle.
Goodbye to the iPod Nano & iPod Shuffle
Review: Apple iPod shuffle (Fourth-Generation)
Apple confirms iPod nano and iPod shuffle have been discontinued - The Verge
Apple releases redesigned iPod nano, shuffle
Identify your iPod model - Apple Support
Apple Has Discontinued the iPod Nano and iPod Shuffle – The Geeks and Beats Podcast with Alan Cross and Michael Hainsworth
Identify your iPod model - Apple Support
List of iPod models, Apple Wiki
Review: Apple iPod nano (Fifth-Generation)
iPod shuffle shortages caused by supplier changes, Apple has no plans to ax its cheapest media player
Apple Discontinues the iPod Shuffle & Nano