Top diameter 3-5/16" bottom diameter 3-1/16" height 7"
This identification is based on mold drawings in West Virginia Museum of American Glass monograph #44, p. 8, on Central Glass Works stemware from the 1930s by Tom Bredehoft in 2005. This stem is not shown in Tim Schmidt's book Central Glass Works, published in 2004.
As an aside, when this stem was decorated by Lotus, Lotus' line number was 24, which unfortunately is the line number Replacements uses as the Central line number.