Boltigen Compressor Sight Glass, 1/2'' NPT Sturdy Brass Clear Dome Bulb Sight Gauge, Oil Level Site Glass, Tank Level Indicator Plug Window, Perfect Replacement for Air Compressor、Pump、Tank

Great quality product. I used as a sight window to my outside electrical panel as a way to see the indicator light on my whole house surge protector. Crystal clear, and water/fluid proof. Works great for the way I repurposeed it.

It takes seconds to lift your eyes and see the top radiator tank has water in the morning. Many drivers are to lazy to climb the side ladder on 30 ton water trucks, remove a cap and check the water level. I'm sure anyone could guess the results of running a Cummins without water & overheating the engine. Anyway, the drivers have said it saves time in the morning and for the small cost it could save hundreds of thousands in motor repairs, down time & lost contracts. These sight glasses are great & I highly recommend them. P.S. The green water stands out so bright I'll know if the additive has been overlooked on servicing.

I needed something to indicate air pockets in my latest experimental solar thermal system. These do the trick. It can be hard to see if there is liquid or air, when the liquid isn't colored. The way I mounted them, about 1/3 water remains when the water is gone. Hence I can see the air, when it is 2/3 air and 1/3 water. Unless you use a colored liquid, you might want to consider that.

Perfect replacement for any OEM Surge Tank sight glass. Larger view of the fluid level with a clear indication compared to the old conical type. It's a win..

Quality construction large sight glass, appears to work with the temperature and pressure of the cooling system

works great in fire apparatus coolant tanks

Excellent packaging /shipping, quality part, would buy again

Perfecto para el uso que quiero darle, como mirilla para el tanque de combustible de mi motocicleta