Cylindrical Peptide Synthesis Vessel with a 2mm PTFE valve and a sealed-in, coarse porosity fritted disc. The fritted disc is positioned so that there is a minimum amount of dead space. The GL-32, threaded top cap includes a PTFE-faced liner. Breakage of glass stopcock arms is eliminated by the PTFE construction of the stem and the valve only requires a 1/4-turn from fully closed to fully open. The valve stem has a 1/4-28 thread on the ID and the OD is sized for a 3/8" compression fitting. All surfaces that come in contact with liquid are PTFE or borosillicate glass.