Description Description Watchgas SST4 PUMP CO/O2/H2S Model: SST4-PUMP-X2ODH-Y Operating Temperature: -20?+60°C / -4?+140°F Humidity: 5?95% RH (non-condensing) Range CO: 0?2000 ppm Range O2: 0?25% Vol Range H2S: 0?500 ppm Size: 150 x 62.2 x 32.4 mm Weight: 275 g