<s>
A	O
keystone	B-Protocol
module	I-Protocol
is	O
a	O
standardized	O
snap-in	O
package	O
for	O
mounting	O
a	O
variety	O
of	O
low-voltage	O
electrical	O
jacks	O
or	O
optical	B-Device
connectors	I-Device
into	O
a	O
keystone	O
wall	O
plate	O
,	O
face	O
plate	O
,	O
surface-mount	O
box	O
,	O
or	O
a	O
patch	B-Protocol
panel	I-Protocol
.	O
</s>
<s>
Keystone	B-Protocol
modules	I-Protocol
have	O
a	O
rectangular	O
face	O
of	O
14.5mm	O
wide	O
by	O
16.0mm	O
high	O
and	O
are	O
held	O
in	O
place	O
with	O
flexible	O
tabs	O
.	O
</s>
<s>
Others	O
only	O
have	O
a	O
jack	O
on	O
the	O
front	O
and	O
employ	O
a	O
different	O
mechanism	O
for	O
hard-wiring	O
signal	O
cables	O
to	O
the	O
rear	O
,	O
such	O
as	O
a	O
mini	O
110	B-Device
block	I-Device
,	O
an	O
insulation-displacement	B-Protocol
connector	I-Protocol
,	O
or	O
a	O
crimp	O
or	O
solder	O
connection	O
.	O
</s>
<s>
Many	O
types	O
of	O
jacks	O
are	O
available	O
in	O
the	O
keystone	B-Protocol
module	I-Protocol
format	O
,	O
limited	O
mainly	O
by	O
their	O
physical	O
size	O
,	O
including	O
:	O
</s>
<s>
8P8C	O
(	O
RJ-45	O
)	O
modular	B-Architecture
jacks	I-Architecture
(	O
computer	O
networking	O
)	O
,	O
unshielded	O
for	O
UTP	O
cable	O
and	O
shielded	O
for	O
STP	O
.	O
</s>
