SO2 upgrade module (0-5000 ppm 1 ppm res.)$1,880.00 For Testo 350 and Testo 340 – SO2 upgrade module (0-5000 ppm 1 ppm res.) Call us for a quote Product Model: 0554 2252 SO2 upgrade module (0-5000 ppm 1 ppm res.) quantity Add to cart SKU: 0554 2252 Category: Testo Sensors Parts & Accessories Tag: Testo Sensors Parts & Accessories Related products Connector cable high pressure probes0 out of 5 $182.00 Add to cart Testo 350XL/335 CO replacement sensor (0-10000 ppm H2 compensated)0 out of 5 $1,264.00 Add to cart CO Sensor – 327-10 out of 5 $96.00 Add to cart