Is this the yellow bodied, black headed sensor on AliExpress at £1 (approx)?
I couldn't see where you adjust it, but frankly, at that sort of price, you aren't going to get a lot.
A multi-turn potentiometer, the type with a body and 1/4" shaft, pretty expensive, wire wound, will have stops, as will the lead screw types.
On this sort of item, as in PIR motion sensors used for lighting or burglar alarms, they tend to use 270 degree singe turn pots with stops.
I must admit I have never seen one of these setting pots without stops. Maybe they haven't bothered.