Abs sensor fitting

Hi all,
Can anyone tell me how the ABS sensor is fitted to the hub,
e.g. is it just pressed in, or glued in, how does it maintain its postion, also I believe it takes its electrical signal from the toothed portion on the uj, therefore the air gap between the tip of the sensor and the teeth is all important. But does the sensor push down to a stop (shoulder) or can it actually pushed in to far so that it will touch the teeth ?

this is on 96 discovery

thx in advance
Red.

just push it in til it contacts sensor ring,ie:it wont go no further.It gets knocked back to the correct air gap automatically.No glue,just shove

It is a very tight fit, may need a tap from a hammer on a suitably sized punch to push it home