Klein Tools ET110 CO Meter, Carbon Monoxide Tester and Detector with Exposure Limit Alarm, 4 x AAA Batteries and Carry Pouch IncludedThe ET110 CO Detector is an easy-to-use meter that detects and measures concentration levels of carbon monoxide (ppm) and temperature (Fahrenheit/Celsius), making it the perfect choice for HVAC professionals. Features backlit LCD screen, warning indicator light, audible and visual alarms and multiple function buttons. Includes carrying pouch and 4xAAA batteries. Carbon Monoxide Tester detects and measures CO gas concentration. Backlit display with CO measurements from 0 - 1000 ppm. Carbon Monoxide Meter with audible and visual alarms. Auto-power off after 20 minutes of no usage helps conserve battery life. Includes carrying pouch and 4xAAA batteries. Meter is NOT intended for use as personal protection equipment. For more than 160 years, Klein Tools has manufactured premium-quality, professional-grade hand tools that deliver the performance, durability and precision needed to get the job done right. Our family of engineers, workers and craftsman continue to put six generations of expertise into every tool we create by using only the highest quality materials, superior workmanship, and keeping manufacturing as close to home as we can. Klein isn't just the name of our company, it's also our family name. And since we're an American company that's family-owned and family-run, you know you can count on us to be here tomorrow. Klein Tools doesn't just make great products, we make great products that stand up to the demands of the professionals who use them every day ... Since 1857.Klein Tools RT250 GFCI Receptacle Tester with LCD Display, for Standard 3-Wire 120V Electrical OutletsThe RT250 is an electrical receptacle tester that tests the wiring conditions at an electrical outlet and inspects GFCI devices. The LCD displays the voltage, identifies the wiring fault, and the time required to trip a GFCI device. It is designated for use with North American 3-wire 120V electrical outlets. GFCI electrical circuit tester inspects GFCI devices. Easy to read LCD display shows voltage, faults, GFCI trip time. Identifies common wiring faults on North American 120V outlets. Bright green and red LEDs illuminate for visual indicators. CAT II 135V safety rating. Durable 6.6-Foot (2 m) drop protection. For use on 3-wire, North American 120V electrical outlets only. For more than 160 years, Klein Tools has manufactured premium-quality, professional-grade hand tools that deliver the performance, durability and precision needed to get the job done right. Our family of engineers, workers and craftsman continue to put six generations of expertise into every tool we create by using only the highest quality materials, superior workmanship, and keeping manufacturing as close to home as we can. Klein isn't just the name of our company, it's also our family name. And since we're an American company that's family-owned and family-run, you know you can count on us to be here tomorrow. Klein Tools doesn't just make great products, we make great products that stand up to the demands of the professionals who use them every day ... Since 1857.