Measures CO from 0-1000 ppm and features an electrochemical sensor that responds very quickly to ambient changes in CO concentration without the use of a pump. Results are displayed on a large, backlit LCD display. In addition, an audible beeper (can be silenced if desired) triggers with increasing frequency as CO levels increase. A Max Hold function stores and displays the maximum CO level. Unit operates on 9V battery (included) and weighs 1 lb. Comes complete with manual and C50 (123-381) carrying case. An optional Aspirator Kit (409-545) can be used with the meter to reliably draw hot flue gas samples up to 700*F (370*C). It features a stainless steel sampling tube, industrial grade aspirator and a replaceable particulate filter.