Please choose what you need correctly, if you have any problem, just let me know. Supply Voltage range : AC 80V260V; 5060Hz, UK, US, EU Plug availablePower consumption: 15VA. Operating temperature: 045 degree centigrade. Storage temperature: -3070 degree centigrade. Relative humidity: Less than 90%. Readout allowable input signal: TTL square wave. Allowable input signal frequebcy: Less than 5M Hz. Max resolution of digital display length. 5µm (0.005mm/0.0002). Min resolution of digital display angle :0.0001/pulse. Digital Readout Dimensions:29517065mm (11.6″6.7″2.56). Linear Scale Interface: DB9(RS232). Display Advantage: Having a good capacity of resisting disturbance, durable keyboard, easy to change. SDM 200 sets memory, power-off memory for 10years, circumference drilling, oblique line drilling, 1/2 centering. The simple R function. Chambering (applicable to: Milling machine, Boring machine). Tool conpensation (for lathe). Machining of oblique plane. Also a calculator is equipped for more convenient usage. (1) Digital display to eliminate backlash and improve precision(2) Advanced trigonometric calculation so to accomplish a perfect project. (3) 11.6wide display to offer excellent long-distance viewing. (4) Digital readout kit can avoid wasting weeks to check machine precision. (6) 1pc digital readout(2Axis/3Axis) with scales(upon your options), 5? M (0.0002) resolution (at 45ºC). Q1 : are the length 100, 150, 200…. 1000mm travel length or total? Answer : all are travel length. Q2: if i need 200mm, 450mm scales with 2axis digital readout, how should i do? Q3 : what does the dro measure to? Answer : measure to 0.005mm, 0.0002inch (1inch=25.4mm). Q4 : if i need a scale like 255mm, can you offer it? Answer : 250mm is enough, its measuring range can reach up to 270mm, so you can use if you need to measure 255mm. Q5 : Can i cut the scales by myself? Answer : Technically NO, it maybe unavailable after cutting. Q6: Do you have English user manual? Answer : yes, it comes with the dro box. Q7: Do you have other higher precision type, such as measure to 0.001mm? Q8: Is it easy to install these scales and dro? Answer : Please must check the scale pin definition (1,2,3,4,5,6,7,8,9), which is very important!!