from the days of fighting the old man on kit we use I install wise didn't want to use it. As was expected I lost an we fitted em.
We then had to remove them all due to FA's
that was then.
Now in recent times things are different sia don't use em but sw does.
Its not the number 1 detector returned as unfit but brand wise its top 2.
id add look at numbers, how many fail vs how many fitted?