The Corning size GL45 linerless replacement cap has a polypropylene body and a plug seal. This cap secures contents of media bottles to help prevent spills and evaporation. The polypropylene cap provides solvent resistance, strength, and thermal performance during hot applications, is lightweight, and can be sterilized and autoclaved. This cap has a plug seal that presses against the rim of the bottle to provide a tight seal and a barrier against moisture and gas. It is designed to fit thread size GL45 Corning Pyrex media bottles (sold separately).

Lab bottles are used to store, hold, and mix liquids, powders, and other substances in a wide variety of scientific industries. Lab bottles have a more pronounced neck and shoulder than jars. Lab bottles are manufactured with a combination of characteristics in order to meet the demands of particular applications, such as for solution dispensing, mixing, and weighing, and use in centrifuge operations. They come in many shapes for specific applications, with a variety of mouth or nozzle shapes and sizes for specific use. Lab bottles are made from materials, such as glass (borosilicate or soda-lime) and an array of plastics, which are selected for chemical and thermal expansion resistance, transparency, and their adaptability in a variety of applications. Lab bottle interiors, caps, and lids are often lined with a protective material. Caps and lids help seal bottles to prevent solutions from spilling. The capacity refers to the fluid amount held by a lab bottle, and is commonly measured in milliliters (mL) and liters (l), and sometimes in ounces (oz). Lab bottles are suitable for use in chemistry and biology applications, as well as in pharmaceutical and scientific testing.

Corning manufactures consumable glass, ceramics, and plastic laboratory tools for life science research, industrial, and educational applications. The company, founded in 1908, is headquartered in New York, NY, and makes ISO-certified products.