Dwyer® Red Gage Fluid, A-101, 1 oz Bottle, .826 Specific Gravity

This is pricey but it's the exact match

Hard to find fluid additive but exactly what the gauge required!

This gage fluid is widely used in Dwyer pressure gauges used for radon mitigation systems. Over a period of years, the level goes down and it needs to be refilled. You can do it yourself! Just disconnect the tubing, add this fluid through the fill port, and adjust the knob to set the zero level. Then reconnect the tubing and you're done. The main mistake you can make is to add too much, in which case you'll need to fish a piece of paper towel (or pipe cleaner) down into the fill hole to remove some excess. I made that mistake, but even so, the whole process was 10 minutes.

The bottle I received from Norkan did not have the dropper cap as pictured. The product was 1 oz. I used a small eye dropper to add the fluid to my radon gauge.

Does what it was intended to do

Arrived quickly and was just what we needed to replace fluid in a radon mitigation system when the guage was moved and spilled.

Gage for measuring inches of pressure/

See above!! Item, Not required with Dwyer model 25 manometer ordered . Amazon makes it look like it should be ordered!!!