The M1234BK is a black PP plastic 18-400 ribbed skirt dropper assembly with rubber bulb and 49 mm straight tip glass pipette (fits 5 mL glass euro bottle). Dropper assemblies are composed of a number of parts: the cap, the bulb and the pipette (tube). The length of the entire dropper is 67.8 mm (2.67 inches). The pipette length is 49 mm (1.92 inches). Dropper assemblies are used with liquids that require precision and intricacy when using the product. Polypropylene (PP) is marked with the resin identification code of 5. PP is less flexible than LDPE, somewhat stiffer than other plastics, reasonably economical, and can be translucent, opaque, or of any color. PP has very good resistance to fatigue, and has an extremely high melting point (320 degrees Fahrenheit or 160 degrees Celsius).