Laboratory Flask Glassware is used for containing, holding, accumulating volumetrically measuring chemicals, solutions, and other specimen. A wide variety of Flask is demanded for assorted laboratory experiments and preparations such as Single Neck Round Bottom Flasks, Double Neck Round Bottom Flasks, Erlenmeyer Narrow Neck Flask, Reaction Flasks, Kjeldahl Flask, Powder Flasks, Retorts, Dewar Flask, and more. Laboratory Flasks are available in varied sizes, specified by volume it can hold. The metric units are milliliters (mL or ml) or liters (L or l). Laboratory flasks are conventionally made from glass but sometime plastic is used as a substitute.