Made my own puller/installer and I wish the spacer centering tool was included with the bearing kit(the tool would be about 25 cents worth of plastic) but I made one out of a couple of toilet paper tubes. Just slice the tubes lengthwise to remove enough girth that one will fit in the larger front bearing bore and the other in the rear, then put the smaller into the larger with slots on opposite sides and assemble rear bearing ,spacer, frt bearing together to figure out the right length of each paper tube. You want them to overlap inside the spacer about an inch while being flush to the back of the rear bearing and stick out about an inch beyond the front bearing. Once you pull the rear bearing in place you can install your homemade tool with spacer from the front and the start the frt bearing onto the projecting tool and assemble your press and pull the front bearing in. I felt both my bearings seat quite distinctly when I pulled them in and at that point the spacer was held firmly enough that it didn’t drop when I removed my toilet paper tube tool! ALSO- I’m leary of the Chinese bearings too bad they don’t use NSK like the originals. We got eighteen years out of them while raising two girls one of which came from China so i hope the bearings are made as well as the kids!!