GM812-L lens reading distance is 7-50cm.(The actual data depends on the size and content of the code)GM812 series bar code reader module is a high performance scanner, can read 1D bar code easily and read 2D bar code with high speed. It also high speed for linear code, even for bar code on paper or screen.GM812 series bar code reader module is an advanced bar code decoding algorithm which developed on recognition algorithm, can easily and accurately read bar code, simplify secondary development.material: metalColor as shownPackage Contents:1 pcs Scanner ReaderOnly the above package content, other are not included.Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.