API Replacement Test Tube

I've been using these replacement tubes for a few weeks now and the glass is noticeably thicker than cheaper alternatives I've tried, so they feel sturdier when swirling test water. The fit is perfect with my standard kit and they haven't clouded or cracked after multiple uses.

I dropped my old tube and it cracked, but this spare fits snugly into my test kit's tray and holds the 5ml line perfectly for my weekly pH checks.

These tubes fit perfectly into the standard test kit case, and the glass is noticeably thicker than the originals so they don't feel as fragile. Just what I needed to replace a cracked one without buying a whole new kit.