Tolerances and measurements seemed accurate but there were burrs on the inside where the screw holed are tapped that I had to file off before a 5mm rod would fit in.
Pros
The blue aluminum casing of these couplings provides exceptional strength and durability. It can withstand high levels of torque and vibration, ensuring that your motors and wheels are securely connected and won't come loose even during the most demanding applications. Additionally, the rigid connector ensures that the coupling stays in place, providing a reliable connection that will last for a long time
Cons
The blue aluminum casing may be prone to chipping or scratching with wear and tear, which could affect the overall durability and appearance of the couplings