People tell me and I see them in my shop when decks come in that these customers put the push on roller from that e bay idiot that sells them. Right away the rollers go to Terry and the push on junk goes into the garbage which it is from day one. I have tested them and they are NOT any good and present irregular pressure and since they are not bonded to the bearing like they are suppose to be they present phase error that is almost laughable. Instead of a little 15* phase error these junk products will give you more than 160* and the phase shift is even hard to deal with. You can only guess at the azimuth when using one of these rollers. Listen to me a Technician for these machines for 47 years- DO NOT USE PUSH ON ROLLERS!