RKIâ€™s GX-2003 five-sensor personal gas monitor with pump pulls samples from up to 50 feet and measures 100% volume combustibles as well as LEL, O2, CO and H2S. Weighing 11 ounces, the unitâ€™s LCD displays all gas readings, battery level and time. Standard alarms include vibration, visual and audible. Operates on Ni-Cad pack or AA alkaline batteries. RKI Instruments, Inc., Hayward, CA.