Adapters are designed to provide a very large, vacuum-tight opening between rotary evaporator vapor duct tubes and flasks. A polyacetal clamp acts as a joint retainer and allows the adapter to be extracted from the glassware. Simply unscrew the flask from the vapor duct to remove sample or use a 45mm, PBT cap with a PTFE-faced liner for storage. Adapters are supplied with threaded caps and keck clamps.