This is a review for "5 Metaltex glass milk saver boil boiling water alert pan pot 
watchers" at £8.99 wich is £1.80 each.
I bought them in October 2016 from Amazon sold by MightyHousewares.
As you can see it's come well packaged, and it's marked clearly that it is fragile, because
the items inside are made of glass.
Plenty of bubblerap to stop the glass from getting banged about and broken.
So each pot-watcher comes on a separate card which it is laminated to with a bit of plastic
So on the back are the instructions of how to use the pot-watcher in all the different languages.
unfortunately I failed to get it into focus when I was filming the unboxing.
So I took a photograph later after I had cut the
pot-watcher out of the
laminated card
So what it says is: "Boil over preventer. Warns you when liquid 
is beginning to boil, make of hygenic and heat proof glass.
just place in bottom of Pan and wait till it starts to sound. Make sure that the disc has cooled down
 before washing it.
So it's well packaged and sealed from the outside world
and contamination on it's card with a sort of plastic vacuum packed
round it so you will need a pair of scissors to cut it out.
so it's a solid piece of glass it ways 78g 
and it feels quiet sturdy I  guess it has to 
to survive in a pan boiling away
and all that knocking about as you don't want broken glass in your boiling milk or water 
So it's like a doughnut shape, a really skinny doghnut with a big hole except the hole isn't a hole it's solid.
So it's just over 3 inches in diameter that's about eight centimetres, and it's
a centimeter thick on the thickest part the outer rim.
the outer rim is cylindrical and of the diameter of about 1 cm and in one 
part of the rim there is sort of a pinch were it gets thinner
probably to allow bubbles to escape to make it vibrate in the pan.
So  I didn't buy the pot watcher to watch pots.
I bought it to use to hold down fermenting vegetables in jars, I wanted something disc
shaped, solid and preferably made of food grade glass so the pot watcher seemed ideal.
So it needed to fit in the jars in which I ferment vegetables
So the jars I use come in all different shapes and sizes.
as you can see this one has got 
quite a norrow neck, so
the pot watcher isn't going to work for that one, where as this one is a Kilner jar with a clip top
with a rubber seal that I like using for fermentation
and this one's got a nice big wide top and hopefully the pot-watcher is going to 
fit in there yes it does, it's the perfect size.
There is another type of Kilner jar slightly different than the last,
 but it's got a wide top again, 
so the pot-watcher fits that one perfectly as well so it is looking good.
So I have got some fermenting veg on the go, this a batch of kimch which 
I have done, in one of the narrow necked jars so the pot-
watcher is no good for that one, but I have also got some
in the other type of jar, the clip top,  with a wide neck
so lets see if I can use the pot-watcher for the purpose I bought it for.
so I usually just use a shot glass to press the
veg down under the water because they need to be kept under water
now I can use that in conjunction with the pot-watcher, so that's 
going to keep everything under the the liquid.
It's just the right size so it's perfect
Yes that's a really good buy for this purpose because fermentation is an anaerobic process so
want to keep the vegetables under liquid so it doesn't come into contact with 
oxygen and so the veg doesn't become mouldy so that
pot-watcher will keep all the veg under the liquid, and keep it safe
from nasty bacteria.
