This design is similar to the CG-1320, but the inner vapor tube is sealed to the top of the trap to prevent entry into the condenser. This provides expanded volume for reactions that have a tendency to foam excessively. The vapor tube has 2 large holes; see CG-1319 and CG-1321 for modified/improved versions.
The top outer joint is a 24/40 standard taper on all versions. This item is available in 100, 250 and 500 mL capacities with a variety of lower inner joint sizes.