Similar to CG-1239, but with the condenser being a combination of a cold coil and Leibig. Water flows into the coil through the middle hose connection and exits the outer jacket through to top connection. The lower connection is for use with vacuum or inert atmospheres.
This head is excellent for use when distilling medium to high boiling point solvents. The top outer joint is a 10/30 for use with a 2" immersion thermometer. Also available with Vigreux indentations (not shown) to further improve efficiency.
Application note: Some vacuum distillations need to be performed at a specific pressure rather than full dynamic vacuum. To maintain a relatively low vacuum (~2-50 torr), once can use an adjustable bubbler such as item #AF-0513-A-21 as a low-tech vacuum control (manostat). For those situations where you need to operate at pressures as high as 760 torr or want to avoid the use of mercury (a good idea), consider a Mano-Watch™ vacuum controller/monitor, item #20900-A.