Supplementary material of the paper Bi-Bennetts - Flexible arrangement of two Bennett tubes. The material consists of a video (see or download file bi-bennetts-video.mp4 bellow) and an interactive CAD model, which can be accessed on this link:https://cad.onshape.com/documents/36c3bf58b00e2633d6dd05e0/w/9a1cb7d328f176ab9f779ad8/e/3adbaf520b2e9a36b3a9fc79?renderMode=0&uiState=696e08af81e8b4e0b365288cThe model can be moved by dragging one of the links (except the base link). Close to the fully-stretched configuration of a Bennett 4R loop (i.e. the four common normals of adjacent axes fall into the same line) the CAD model behaves very sensitive, and it may collapse. You can use ctrl+z shortcut to step back up to the initial configuration. Mechanism synthesis and geometric design: Georg Nawratil; CAD modeling and video editing: Daniel Huczala.