Replacement Filter for NO sensor (blocks / absorbs SO2 cross gas)$139.00 For New Testo 352. Testo 340 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 Description Description For New Testo 352. Testo 340 Related products NO low replacement sensor (0-300 ppm 0.1 ppm resolution)0 out of 5 $835.00 Add to cart O2 Sensor 0-21.0 vol%0 out of 5 $93.00 Add to cart Self service replacement O2 sensor – 305/325M & XL0 out of 5 $90.00 Add to cart