29/26 Glass Adapter with All 6 Threaded Vial Adapters: 13-425, 15-425, 18-425, 20-400, 22-400, 24-400. Adapters permit the connection of standard laboratory dram sample vials directly to the vapor tube or a bump trap of a rotary evaporator. Adapters have a top outer joint of the listed size and a 20-400 G.P.I. thread at the bottom. A PTFE-lined, polypropylene, double-threaded connector attaches the vial to the adapter.