The improved telegraph insulator, designed by Jeptha Wade consisted of a threadless mounting bracket, a glass sleeve and a wooden cover.  Insulator collecting hobbyists refer to the smooth glass sleeve using CD 723.3.  This incredibly well preserved example photographed courtesy of the Louis A. Hall collection.

The dot - dash Wade sleeve was probably an improvement over the original smooth sleeve design.  The wooden cover pictured here is an authentic reproduction made in the 1970s by the late Ora Beary, courtesy Ross Baird.  The dot - dash sleeve, CD 723, loaned to us courtesy Joe Nardone.