Unlike
the wooden box mines, the No.4 is durable and the fuze components
are plated to resist corrosion, so the mine can be expected
to remain functional for many years.
The fuze screws into the wall of the internal plastic compartment
(with a rubber "O" ring). Two types of fuze can be used and
the cut-out at the end of the box for the fuze to protrude is
a different shape depending on the fuze. When the cut-out is
a narrow-slot with a rounded end, the fuze is a simple MUV type
with the butterfly pin holding up the lid against the side of
the slots. Pressure on the lid pushes out the pin. When the
slot is a large square-cornered cut-out with moulded lugs extending
to press onto the pin, the fuze used is a variant with a large
firing-pin retainer made of bent steel strip rather than wire.
The detonators used are reported to be MD-6N types with a thread
at both ends. The MUV type fuze can be disarmed by inserting
a safety pin through the striker, but the variant cannot be
safely neutralised.
In
Lebanon, a variant has been found with a matrix of 3mm metal
cubes fixed to the lid of the mine. This effectively turns the
blast mine into a crude fragmentation device. An example is
shown below. The matrix appears to be held under a thin steel
sheet that is riveted to the top of the mine.
