Donut-shaped elastic torus and its cross-section.

Torus - Wikipedia

Torus -- from Wolfram MathWorld

Fabrication of Drug-Loaded Torus-Shaped Alginate Microparticles and Kinetic Analysis of Their Drug Release

Torus -- from Wolfram MathWorld

Takahiro TOMIOKA, Professor (Full), Doctor of Engineering, Akita Prefectural University, Akitashi, Department of Mechanical Engineering

Map of Torra, the donut planet. Top layer is outside, bottom layer is inside, all continuous : r/worldbuilding

Toroidal Transformer: What Is It? How Does It Work? Toroids

Torus - Wikiwand

Shapes : Bully For You

Can one calculate the volume of a torus by pretending it's a cylinder? - Quora