Amazon.com: LEGO TECHNIC 100 pcs BLACK AXLE SIZE 4 STUDS STUD LENGTH Cross Rod Short Mindstorms robot motor part piece 3705 NXT ev3 robotics : Toys & Games
MOC 10PCS Replaceable Assembles Particle 50450 Axle 32 Bricks Building Blocks Part Toys Children Gifts| | - AliExpress
LEGO Technic Through Axle Connector with Bushing (32039 / 42135) | Bricks-Shop