User's Manual

8
4.3 Manual Precision 406 in enclosure
Customers who need to mount their Precision 406 in an exposed position can select
the protective enclosure without an HRU fitted (406c). This means that the Precision
406 EPIRB will
not
float free if your vessel sinks. This is known as a category 2
EPIRB. You can tell which enclosure you have by reading the category from the front
of the enclosure:
406a
Category 1 HRU fitted Automatic float-free
406c
Category 2 No HRU fitted Will not float free