Wheaton Lab 45 Media Bottles are manufactured from USP Type I borosilicate glass. These versatile bottles have a 45 mm screw thread finish a large writing area and approximate volume graduations. The wide 45 mm finish facilitates filling and retrieval of contents. Sloping shoulders allow for easy cleaning and complete drainage while the polypropylene pour ring eliminates dripping. The Lab 45 is available with a white polypropylene cap and pour ring pre-attached. Caps and pour rings may be purchased separately. the cap has a built in wedge shaped sealing ring, eliminating the need to a liner. Lab 45 is also ideal for freeze-drying when used with 224100-503 or 224100-507 slotted stoppers and a 240736 screw cap. The bottles, cups, and pour rings are autoclavable.