The DP834WH is a white PP plastic 24-410 ribbed skirt down-lock saddle head dispensing pump with 7.75 inch dip tube (1.8 - 2 cc output). Down-lock pumps, when fully depressed and twisted, can be locked to prevent accidental dispensing. This closure fits containers with a 24-410 neck finish. The first number is the diameter of the container's opening (in mm). The second number refers to the thread/style/depth of the closure's skirt. This pump is made of polypropylene (PP), which means it has a high heat tolerance level and an excellent resistance to fatigue. Dip tubes can be trimmed to fit smaller shorter containers.