Two Parallel Necks Claisen Adapter, 19/26 Socket and 24/29 Cone, Borosilicate Glass

This Claisen adapter from Eisco Labs is made from heavy-duty borosilicate glass and features two parallel necks with 19/26 socket joints and a single 24/29 cone joint at the base. The adapter converts a single-neck flask into a two-neck configuration. Claisen adapters are used in distillation and reflux setups where simultaneous connections are needed — for example, fitting both a condenser and a thermometer or addition funnel to a single round-bottom flask. The parallel neck arrangement keeps the connected glassware aligned and compact. Borosilicate glass is autoclavable and chemically durable with low thermal expansion. Heat tolerances are: strain point 515°C, annealing point 565°C, and softening point 820°C.