Borosil Reagent Bottles Narrow Mouth With Screw Cap, Amber Capacity 50ml, 1519012, are used to suspended in liquid materials. Bottles have multiple uses, as Aspirator, Reagent and Solution Bottles. Bottles are not used for direct heating purpose. They are designed with heavier wall thickness, making them mechanically stronger to withstand wet or dry sterilizationSupplied with screw caps and pouring ring made of polypropylene, autoclavable at 121CPrinted with graduations and retrace code using a durable white enamel100 ml to 20000 ml Bottles have unifor m GL 45 threadMechanically strong and chemical resistant Uniform amber colour protects media from light radiation with a wave-length between 300 nm and 500 nm Ideal for use with light-sensitive media and for the long-term storage of substances