BrickLink - Part 42003 : LEGO Technic, Axle and Pin Connector Perpendicular 3L with 2 Pin Holes [Technic, Connector] - BrickLink Reference Catalog
LEGO Sets with Part 42003 Technic Axle Joiner Perpendicular with 2 Holes, and Pin Connector 3L Pin
LEGO® 42003 4175441 - 4200324 - 6273711 - ToyPro
LEGO® 42003 4173970 - 4200326 - 6273708 - ToyPro
Moc Building Blocks Self-locking Bricks Technical Parts Technical Connectors Part A Compatible With Major Brands For Kids Toy - Model Building Kits - AliExpress