Qesdaoxu 6PCS Thick Glass Graduated Dropper Pipettes Fluid and Liquid Pipettors 0.5ml 1ml 2ml 3ml 5ml 10ml with Caps and 2PCS Washing Brushes (20cm-7.8inch)

Llegaron bien a pesar de ser de cristal

I can't tell you how precise these are; I'm not working in a lab, but Bomex seems to make pretty accurate tools for an amateur chemist like me. I've combined these with a serological pipette controller (check out Levo's model for around $25) and it's like magic. I plan to throw the included bulbs away soon, but the pipette cleaning brushes are wonderful. With the pipette controller I can pickup precise amounts of fluids and deposit them at my leisure, then clean and reuse these glass pipettes. They will chip on the tips if you're not careful or break entire if you're reckless; I just bought a second set to have backups. For $15 shipped, this set is worth every penny. I hope this helps you.

I bought these for a project. They work well but capacity is very small. See the description. Overall good product. Heavy glass for size.

Esta muy excelente el pack de cuenta gotas

These are very helpful when I’m trying to separate water based liquid from oil and for approximate measurements. If I broke them all I’d probably buy them again cuz they’re a good price. I haven’t tested their accuracy as it’s not an important factor for my purposes, but if needed precise volumes I don’t think I’d have a lot of confidence In their accuracy, especially with the bigger ones. Really accurate pipettes are narrower, with more precise graduation. I prefer to use a graduated cylinder or syringe when I need accuracy. The one major problem I have with these pipettes is the bulbs—especially the smaller ones—will slip off when exposed to oily substances or solvents. Once it does slip off both parts have to be washed or the bulb won’t stay on at all. So while it’s helpful that there are several more pipettes to switch to in case this happens, it is still a major annoyance. Honestly I haven’t used many pipettes since high school (long ago) but based on my limited experience I’d say these are more suitable for use by a 5th grade science class than for college level or professional lab use. For projects like mine tho, using mostly harmless ingredients or occasionally the kind of chemicals you can buy at the hardware or grocery store, they might actually be more practical than the professional kind cuz you get the volume without the awkwardly long glass piece. COVID got me started on several messy projects (eg soap making, herbal infusions/extraction, etc.) and these have proved very helpful—enough to make up for their shortcomings. I mean I’d definitely rather have them than not.