With an outer joint at the top and an inner joint at the bottom. Use of these adapters will permit utilization of existing labware in many combinations not otherwise possible. Condensers, for instance, with a 24/40 joint can be used on flasks with a 29/42, 34/45 or even a 19/38 joint rather than having to order additional flasks or condensers for limited use. For convenience we have included both micro sizes and standard sizes in one listing. Many other combinations are available on request.