Lego Parts: Technic Rotation Joint Ball Loop with Two Perpendicular Pins with Friction (PACK of 4 - Black) by Parts - Technic : Amazon.fr: Jeux et Jouets
Is this considered an illegal building technique : r/lego
Ballshaft! | New Elementary: LEGO® parts, sets and techniques
LEGO PART 32474 Technic Ball Joint | Rebrickable - Build with LEGO