Pointed end Pyrex glass rattles for fly tying. These can be pressed into foam bodies for fish attracting noise. Put in the belly of a zonker and watch out. Tough laboratory glass. If it's not Pyrex, it won't last. Great for bass and saltwater patterns and also now used on some Enrico flies.
The mini is 3mm, the standard is 4mm and the large is 5mm. 10 per package.