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 wins high scan 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 Barcode Scanner ReaderOnly the above package content, other products are not included.Note: Light reflection and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.About UsWe provide the good product with the best price,we support Wholesale/Drop Shipping Order1. For Drop Shipping order, please remark"dropshipping order", we will prioritize it.2. For Wholesale/Drop Shipping orders, if you have any ideas about the price or package,please contact us in advance,we will give you the best service to satisfy your demands.About Shipments1.We will send out the orders ASAP once your payment is completed normally.2.Please write your complete delivery address with correct phone number and zip code, especially please confirm your full name.About After-sale ServiceWe are reliable seller and we have our professional after-sale service for all of our customs. If there is any question about the order,please contact us in advance ,we will always here until you get a happy answer.About Feedback1. Please check the package and item when you get carefully to make sure there is no problem.2. If you have any problem or are not entirely satisfied with your package,please don’t be hesitate to contact us first before leaving negative feedback. We will resolve the problem to satisfy you.3. If there is no problem, please leave us five star positive feedback.Your affirmation is our greatest motivation ! ! !