Where do you buy them? I don't have a hobby store inside of a 1-1/2 hour drive, and none of my usual Internet hobby dealers even list these. Those of you with experience using these - why not post what you are using and how you do the installations. It would be helpful for those of us who haven't tried. Are you using the 901, 902? Do these require purchase of draft gear boxes, springs, or what? Mike - NYC1956
The ones I've seen have a draft gear box with them... Try ordering them online via Walthers. I'm not familiar with different types of Z couplers, I think one type is assembled, and the other is unassembled... and no further difference. I'll check my LHS probably tomorrow.