Technical Abs wheel sensor

[Jimsey]

Guys abs , esc, and hill start warning lights on dash , diagnostic says it’s the drivers rear wheel sensor that’s faulty, bought a new sensor , but when taking old sensor off it’s different from the new one , old sensor is more a barrel type shape new sensor is flat with steps on it , when trying to insert new sensor into hole it only goes in so far it won’t go fully home are there different sensors , looking for some guidance ,

 

[ZaphodB]

You'll have to give more info for help, year , model pics of old and replacement etc