2pcs 6mm Flange Shaft Coupling High Hardness Metal Flanged Joint Guide Shaft Support Coupler for DIY Model Shaft Connection

These worked really well with the motor I am using for my Halloween project. The Allen screws (Hex screws) are so tiny I was paranoid that I was going to drop them when trying to fit them into the flange, but all worked out okay. Nicely made coupling.

I ordered this because it claimed 1/4" in the title, but its .24 inches, which is way smaller than what I need.