LEGO part 3711 - Black Technic, Link Chain at BrickScout
Amazon.com: LEGO Chain Reactions (Klutz Science/STEM Activity Kit), 9" Length x 1.06" Width x 10" Height : Pat Murphy and the Scientists of Klutz Labs: Toys & Games
LEGO Chain Reactions | MindWare
Probably a dumb question but.. how are lego chains manufactured? They appear to be seamless. : r/lego