... 3) fast calibration device Product Name: Sales! Portable M40 gas detector (CO,H2S,O2,LEL) M40 SPECIFICATIONS: Size: 4.30" ... Graphic LCD with Backlight SENSOR SPECIFICATIONS: Gas Range Resolution T90 Carbon Monoxide (CO) 0-999 ppm 1 ppm 48 ... to 122ºF),all sensorsper CSA standard C22.2 No. 152,LEL sensor tested to 0ºC to 40 ... free to contact me. Thanks. Sales! Portable M40 gas detector (CO,H2S,O2,LEL)