Replacement Filter for NO sensor (blocks / absorbs SO2 cross gas)$139.00 For Testo 350 and Testo 340 – Replacement Filter for NO sensor (blocks / absorbs SO2 cross gas). Call us for a quote Product Model: 0554 4152 Replacement Filter for NO sensor (blocks / absorbs SO2 cross gas) quantity Add to cart SKU: 0554 4152 Category: Testo Sensors Parts & Accessories Tag: Testo Sensors Parts & Accessories Related products SO2 replacement sensor (0-5000 ppm)0 out of 5 $986.00 Add to cart NO low replacement sensor (0-300 ppm 0.1 ppm resolution)0 out of 5 $868.00 Add to cart Probe extension cable 16′0 out of 5 $135.00 Add to cart