AOQUN Radial tip Round Bottom Volumetric Erlenmeyer Flask Cleaning Brushes allow you to remove difficult deposits without scratching your container. Folding tip and double-tufted brushes are made to fold flat through the bottle neck and expand to fill the container. Angle head brushes are manufactured to angle the brush along the curvature of the container with minimal strain. Volumetric Flask Brushes feature an angled handle which bends to fit the container shape for cleaning pear-shaped, Erlenmeyer flask, round bottom, flat bottom, Nephelo, Kjeldahl, filtering, and volumetric flasks.