Rubber Glassware Cleaner
by Fischer Technical

Made of flexible rubber, these little gadgets easily slip onto one end of a glass or plastic stirring rod. The rubber has been split into 4 vanes that extend outward from the central stem of the cleaner, allowing them to rub back and forth against the glassware as you clean it, without having to worry about scratching or otherwise damaging it. Its rounded tip makes it perfect for cleaning pieces of glass or other labware that has a depression in the base, like test tubes.

It is 30mm wide, and features a 5mm wide channel in the center, allowing it to firmly attach to a stir rod.