Genuine Mazda replacement hub nut. This measures 29mm across flats (29mm socket to remove) It fits the Front hubs of NA/NB 1989-2004 and the rear hubs of NA 1989-1997*
*Mazda did change the size of the rear driveshaft so check - you may need the 32mm nut
A hub nut should not be reused. This holds your whole wheel on and replacing it is good insurance. If you are replacing a wheel bearing, make sure to order a new hub nut