A
rigid
box
____________________
of
steel
which
is
very
common
in
intermodal
freight
transport
.
It
can
be
used
for
transport
by
sea
,
rail
,
air
,
and
road
.
It
is
available
in
many
different
versions
and
sizes
.
For
example
,
there
are
open
-
top
and
flat
-
rack
versions
.
Some
of
them
have
wheels
or
a
bogie
____________________
to
them
.
The
most
common
lengths
are
20
,
40
,
and
45
feet
.
It
is
made
to
the
specifications
of
the
International
Standards
Organization
.