Front
Back
Front Left Detail
Front Right Detail
Back Left Detail
Back Right Detail
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Front
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Front Left Detail |
Front Right Detail |
Back Left Detail |
Back Right Detail |
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No. 255 is a predecessor to No.255D and differs in two ways from No.255D. No. 255 lacks the DI scale on the back. More significantly, trigonometric scales TI2, TI1 and SI are graduated in Radian for 255, whereas it is in more ornate Degrees for 255D. |