For connecting 5835 bottom drip stopcock adapter to bottom of 5862 chromatography column with leak-tight O-Ring seals. One end is #50 Screw thread for connecting to column, the other #25 Screw thread is for connecting to 5835 adapter. #50 end of coupling is supplied with Porosity A glass packing support, press fitted, with taper below disc to #25 I.D. Supplied with (2) FETFE® O-Rings. For replacement O-Rings, see 7855-729 (for #50); or 7855-727 (for #25).