Huion A4 Touch ADJUSTABLE Illumination LED The whole light pad deminsion including black frame is 10-5/8" x 14" with diagonal of 17.7". The Illuminated is 9" x 12.5" with a diagonal of 15.5" Touch Switch Design --- you only need to touch the pad to turn on / off your light box Adjustable Brightness --- simply press the touch switch for several second untill the brigness you want (From Bright to Dark) Memory Feature --- smart memory the brightness of your last use Long life span: 50,000 hours;Suitable for 24hour lighting