| VQ601/3 | SGX Sensortech | VQ1 PELLISTOR, VQ600 HEAD, 0.75" | - | 6,228 | 
                                                    
                            | VQ601/2 | SGX Sensortech | VQ1 PELLISTOR, VQ600 HEAD, 0.5" | - | 8,784 | 
                                                    
                            | T8100 | Amphenol Advanced Sensors | CO2/TEMP SENS WALL MNT DUAL OUT | - | 5,886 | 
                                                    
                            | T8041 | Amphenol Advanced Sensors | CO2 SENSOR DUCT MOUNT 0-10V OUT | - | 2,502 | 
                                                    
                            | KGZ12 | Honeywell Sensing and Productivity Solutions | KGZ-12 HIGH-ACCURACY OXYGEN | - | 3,780 | 
                                                    
                            | MF010-1-LC2 | Honeywell Sensing and Productivity Solutions | MF010 LOW TEMP OXYGEN SENSOR | - | 8,316 | 
                                                    
                            | 314100009 | Seeed Technology Co., Ltd | ALCOHOL SENSOR MQ303A | - | 8,640 | 
                                                    
                            | 27932 | Parallax Inc. | PROPANE GAS SENSOR MODULE | - | 8,460 | 
                                                    
                            | 110-602 | SPEC Sensors, LLC | SENS GAS SULF DIOX ANALG CUR MOD | - | 7,416 | 
                                                    
                            | 110-303 | SPEC Sensors, LLC | SENS GAS HYD SULF ANALG CUR MOD | - | 6,312 |