<s>
This	O
instrument	O
is	O
a	O
mechanical	B-Device
computer	I-Device
for	O
navigation	O
akin	O
to	O
the	O
Norden	B-Device
bombsight	I-Device
.	O
</s>
<s>
An	O
orbit	O
counter	B-Device
labelled	O
ЧИСЛО	O
ВИТКОВ	O
(	O
Number	O
of	O
revolutions	O
)	O
with	O
three	O
digits	O
:	O
two	O
white	O
digits	O
for	O
orbits	O
and	O
one	O
red	O
digit	O
for	O
fraction	O
of	O
an	O
orbit	O
;	O
</s>
<s>
One	O
knob	O
(	O
missing	O
in	O
the	O
picture	O
)	O
presets	O
or	O
resets	O
the	O
orbit	O
counter	B-Device
.	O
</s>
<s>
The	O
IMP	O
was	O
a	O
genuine	O
mechanical	B-Device
computer	I-Device
.	O
</s>
