Pyrex, Watch Glass, 100 Mm

This is visibly out of round and has concentric ripples near the center of the convex surface. I think this will still work for my needs so I will likely not return it, but I am disappointed in the quality. I would not be surprised if these are actually factory seconds or something.

Exactly what I wanted. I use them to cover my teacup when steeping loose leaf tea to keep it hot. After 4 minutes steeping tea with water starting out at 212 F, the glass is hot enough that you'd drop it reflexively if you grabbed it with bare hands. I haven't stressed it any more than that, and don't plan to for my purposes.Ordered Sunday, arrived Friday. They were packed extremely well. Only thing is they were 4 in a plastic bag with no paper in between them, but the set was wrapped super tight in endless special packing paper, and there are no scratches, chips or other defects due to physical trauma that I can see. Those puppies were packed good and tight. I bought 4 for $3.60 each and paid $23.75 total.The glass is clear enough to see through. I can read the ingredients on my candy wrappers with the glass 10-12 inches away from the candy, and the print is quite legible at that distance. With the glass a couple inches away from the candy the print very clear. But the glass is neither polished for optics nor intended for that. The glass has some ripples mainly near the center. You'll be able to see detail through them of anything in a beaker with no problem.The text "PYREX" (with a circled R after it) is in the glass in relief print about 1 cm from the edge on the concave side only. The word is about 18 by 3 mm (I mean it's 3 mm from the top of the E to the bottom of the E). It doesn't impair visibility in any meaningful way. The edges are ground to a curve (near perfect semicircle) and highly polished. They feel like the rim of a high quality drinking glass, although the watch glass is thicker than the lip of a typical drinking glass.The watch glass is 2 mm thick and feels pretty uniform. It feels sturdy enough. I did a drop test from 12 inches onto a wood table covered by a face towel. It landed on the convex side and bounced. It looks like you could drop it 6 inches onto a formica surface, but I didn't try it. Lay it on a table convex side down and the edges are 12 mm off the table.

This watch glass is not round. I attached a picture, but it actually looks worse in real life. It also has concentric, circular ridges on the bottom (also not round) that are obviously a flaw, rather than part of the design. I don’t believe this is actually Pyrex. It is sturdy and would probably work ok for my purposes, but I’m returning it because for this price, it should be much better quality.

I ordered four of these watch glasses as covers for beakers. I wanted Pyrex borosilicate glass. I can't prove they are (how?) but my research convinced me that this is what they are. They are Pyrex brand as embossed on the rim of the glass. Pyrex lab ware (these items) and Pyrex bakeware are not the same - so be sure to research this and get what you want if its important. The edges are rounded (not ground) and smooth to the touch. If you have used watch glasses of this type you know what to expect. If you haven't don't confuse them with a super clear watch glass - these are made as a dish or beaker cover and have some minor ripples so they are not optically clear like a lens but they are clear just to look through. Another nice thing is that the shipping is listed as 7.95, however I purchased four of these and the shipping was still 7.95 for the four (this was Carolina as the supplier). I'm happy these are sold in single quantities as I don't want 10 of them (typical quantity).

Product is quite irregular, not completely or roughly circular.

I wanted the Pyrex brand specifically because I knew it would be good quality and sturdy. The edges were slightly out-of-round, but does not affect functionality.

Fair product. Was somewhat irregular in shape. A little spendy for how irregular and simple the glass is.

This is made of a nice, thick glass. I was surprised that it was a little bigger than I expected.