These are original equipment NOS factory Mopar synchronizer rings for your A555, A568, A523, A520, etc.  They are new OE factory parts.  NOT aftermarket junk made in China.  If you are having your transmission rebuilt there is about a 99% chance the person rebuilding it is NOT replacing your synchro stop rings (i.e.  this part).   Usually a "rebuild" is limited to new bearings and seals, unless you specifically request they replace your synchronizer rings.  Funny thing is...it's your synchro rings that go bad 9 times out of 10 (and hence why you are having someone rebuild your transmission.....so your trans will shift smoother).   We only have a very limited number of these and once they are gone, they're gone.   Price is for 1 synchro ring.