This inexpensive portable titration set features a 2mm straight bore stopcock. The borosilicate glass buret is filled by pressure through a tube extending from the bottle up inside the graduated tube. A small hole in the filling tube at the "O" line permits setting of the liquid level and return of the excess to the bottle. Complete Set furnished with buret, bottle (LG-4230-120 or LG4230-124), rubber hose, rubber stopper (LG-10392-126 or LG-10392-130), and rubber bulb (LG-4340-100). Accessories: Vent Tube (LG-4230-130)