Bought this for our Big Berkey. This is a life saver and a mess preventer! Much easier to read the gauge to know the level of filtered water available rather than lifting the lid and peering into the top reservoir. We also marked the gauge at two points; the first point or lowest on the gauge reflects what level the water is at after filling the reservoir with one 1-gallon pitcher. Once that filtered through, then I added a second 1-gallon fill into the reservoir and marked the next point on the gauge to represent the higher point reflecting 2-gallons of filtered water ready to go. Takes a little time in the day to complete the markings but worth it in the long run to accurately know how much water to fill into the top reservoir and avoid overage in the bottom reservoir. Now anyone in the house can refill the Berkey accurately, using the gauge and water level markings.

Purchased this in March. It worked GREAT at first. No problems and we were able to see the water levels so we knew when to fill the Berkey. Now it's June, about 90 days later. About a week or two ago it started leaking profusely. No matter what level of water was in the Berkey the spigot would leak and leak from the spout. I checked if anything came loose or dislodged and I don't see any issues. I have no idea what happened, but I do know it should have lasted much longer than that. Thank God I kept the original spigot! Now it's past the Amazon return policy and I'm left with a $40 paperweight.

Works as stated by manufacturer. Has annoying physical-illusion after installation because it is never perfectly perpendicular to the tank, as it leans-into the tank at the top of the spigot, like the leaning tower of Pisa. Maybe I have it screwed in too tight? IT STILL WORKS as general indicator of water reservoir. Certainly better than having to lift the upper tank off to see what's accumulated, especially as your filters age you get less volume, even if you clean your filters according to manufacturer's specs. Did you know you're supposed to clean those periodically? Read your product owner's manual !!! Nothing beats a Berkey and I couldn't do without this indicator since I'm a detail man. GET ONE YOU DESERVE IT.

The sight glass is a big help. I have overflowed the Berkey twice now, but that is because I was not paying enough attention. I know that the sight glass has prevented many many overflows. It works great and was easy to install. We tried using the hardware that came with the Berkey and it's spigot, but you really need to use the hardware that they send with it. (They actually knew what they were talking about! Go figure.:)

I just purchased this sight glass spigot from this seller for a Big Berkey I bought. It arrived fine and in good time. The package arrived with the spigot and plastic nut with two washers. I read the instructions as well as looked on youtube how to attach this without breaking the nut. There are good instructions on youtube, but what I discovered is that with this spigot came two washers that were both FLAT washers. One a little thicker than the other one, but both flat. The Berkey instructions I received with the main filter mention a washer that is beveled for the spigot...this beveled washer goes on the outside and a flat one on the inside - then hand screw the nut till tight. I put the spigot together, used it for about 10 days and then woke up to my counter floating with water. There was a drip drip drip from the spigot where it attaches to the bottom part of the filter. I thought I would just have to tighten it, but after tightening it as hard as I could with my hand to no avail as it kept dripping. I used a plier to tighten it tighter, but still a drip! Then I read again about the beveled washer. So I found the original spigot that came with the Big Berkey and there was in the package a beveled washer! This fit the glass spigot with the bevel side facing the container, the flat washer I put back on the thread inside the bottom part and hand threaded the spigot on as tight as I could hand tighten and ol and behold - no leaks! This glass spigot needs the beveled washer that DID NOT come with this spigot. So my advise is to contact the seller to make sure that you get the right washers! Sorry this is so long, but if I hadn't had an unused basic Berkey spigot from another source, I would not have been able to stop the leaking. It has been almost 12 hours now and no leaks.