uxcell V623 V-Groove Guide Pulley Rail Ball Bearings 3mmx10mmx3mm Carbon Steel Miniature Bearings 10pcs

I used a number of these groove pulleys to build my own hand-held guide for controlling how I wind magnet wire onto a bobbin with a coil winder. They not only guide the magnet wire perfectly, but relieve the majority of friction that you would normally used with your hands. I bought 10 of these pulleys, but only needed 5 because I wasn't sure that some of them would function properly. As it turned out, there was only 1 that had some internal problems, the others worked just fine. As you can tell in the pic, I used some nylon standoffs with small bolts, washers and nuts to mount them onto my fixture. They seem to be well made, I'm very happy with them!

Mostly satisfied but got two different sizes of item will be helpful to get the right product that I ordered