LEGO Part 42003: Technic, Axle and Pin Connector Perpendicular 3L with 2 Pin Hol | eBay
LEGO® 42003 6097398 - ToyPro
Self Locking Bricks MOC Technical Parts Connectors 20pcs CROSS BLOCK 3M Building Block Pack for Kids Compatible with Lego 42003|Model Building Kits| - AliExpress
LEGO Dark Blue Cross Block 1 x 3 (42003) | Brick Owl - LEGO Marketplace
LEGO Black Cross Block 1 x 3 (42003 / 42796) | Brick Owl - LEGO Marketplace
BrickLink - Part 42003 : LEGO Technic, Axle and Pin Connector Perpendicular 3L with 2 Pin Holes [Technic, Connector] - BrickLink Reference Catalog