Thistle tube funnels, available with or without taps, feature a long tube that ends in a reservoir bulb with a flared rim. These funnels allow for the insertion of small volumes of liquid to an exact position in an existing system or apparatus. Thistle tubes are specifically designed to fit in Erlenmeyer and other flasks, making the addition of new materials to burets and narrow neck containers easier. Available in glass or plastic, thistle tube funnels minimize the risk of reaction occurring too rapidly and boiling over.