Yealink EXP40 IP Phone Expansion Module Price in London, UKYealink EXP40 IP Phone Expansion Module Technical Specifications Display 160320 graphic LCD with 16 level grayscales LCD Backlight Two page views are possible Different icons for each function shown on the LCD Feature Keys and Indicator 20 physical keys each with a dual colour LED 20 additional keys through page switch 2 independent control keys are used for fast switch pages Programmable for shared line, BLF List, call park, conference, forward,