I'm turning one of those Halloween shop pop-up skeletons into an acoustic animatronic figure for my garden. To keep the joints moving smoothly with little resistance to the servos I used these bearings. I 3D printed the holder and put in the bearings, then I glued this whole assembly into the hinge for a complete replacement. These bearings worked great, were really inexpensive and seem to survive the skeleton I use them in. Can't ask for more.