<s>
TO-66	O
is	O
a	O
type	O
of	O
semiconductor	B-Algorithm
package	I-Algorithm
for	O
devices	O
with	O
three	O
connections	O
,	O
such	O
as	O
transistors	B-Application
.	O
</s>
<s>
The	O
shape	O
is	O
similar	O
to	O
the	O
TO-3	B-Algorithm
package	O
,	O
but	O
the	O
size	O
is	O
smaller	O
.	O
</s>
<s>
The	O
TO-66	O
package	O
is	O
made	O
entirely	O
of	O
metal	O
and	O
is	O
commonly	O
used	O
by	O
silicon	O
controlled	O
rectifiers	O
and	O
power	O
transistors	B-Application
.	O
</s>
<s>
In	O
Europe	O
,	O
it	O
was	O
popularly	O
used	O
by	O
the	O
complementary	O
germanium	O
power	O
transistors	B-Application
AD161/AD162	O
.	O
</s>
<s>
The	O
metal	O
case	O
forms	O
the	O
third	O
connection	O
(	O
in	O
the	O
case	O
of	O
a	O
bipolar	O
junction	O
transistor	B-Application
this	O
is	O
typically	O
the	O
collector	O
)	O
.	O
</s>
<s>
TO-124	B-Algorithm
increases	O
the	O
maximum	O
thickness	O
of	O
the	O
base	O
plate	O
from	O
to	O
and	O
the	O
maximum	O
total	O
height	O
from	O
to	O
.	O
</s>
<s>
The	O
different	O
outlines	O
are	O
now	O
defined	O
as	O
variants	O
of	O
TO-213	O
:	O
TO-66	O
is	O
renamed	O
to	O
TO-213-AA	O
,	O
TO-123	O
to	O
TO-213-AB	O
,	O
TO-124	B-Algorithm
to	O
TO-213-AC	O
.	O
</s>
