WHAT DOES MAZDA 13B REW MOTOR FOR SALE MEAN?

my son will need an engine for his car so we took a chance ,and all I can say is up to now so good .it absolutely was delivered in the well timed method and once we received it in and hooked up and anything that that goes with that back again in place it operate like a new a single .as of today I would definantly purchase yet again and I is going t