When Sheaffer brought streamlining to pen design with the introduction of the Balance at the end of 1928, it stole a march on its competitors. Wahl-Eversharp struck back fast, however, introducing its own streamlined model that same year. The new pen was part of the Personal Point line, and was called "Equi-Poised". Collectors now typically refer to them as "Equipoises", following the example set by Cliff Lawrence in the early 1980s.
The original Equi-Poised, as shown in Wahl-Eversharp's general catalog #298 of 1929, looked extraordinarily Balance-like, and the description in the text even went so far as to explicitly define "Equi-Poised" as "equally balanced". Although "Balance" is now standard collector terminology, Sheaffer used "Balance" and "Balanced" interchangeably in contemporary advertisements. Both were registered trademarks, and the taper-ended Balance profile was protected by a design patent. Not surprisingly, Sheaffer's lawyers were soon in contact (for the full story, see Daniel Kirchheimer's Featherweight vs. Heavyweight). It is probable that the modified version shown below was an attempt to stay within the law without entirely abandoning the basic design.
These "blunted Balance" pens are uncommon, but significantly more common than the Balance clones shown in the 1929 catalog -- suggesting that the blunting of the ends did manage to buy Wahl a bit of time. And indeed, before the original Equi-Poised had been out a year, it was replaced once and for all by Wahl's own patented design (D81,223, filed Sept. 23, 1929): the classic Equi-Poised, as shown at top, with an evenly tapering cap and a cylindrical barrel with an evenly tapering end (note that trim and clip placement may vary). This final version remained in production for several years, although by 1932 only pens without the Gold Seal emblem were listed in Wahl-Eversharp catalogs as "Equi-Poised" (those with the Gold Seal were called simply "Gold Seal pens"). Nonetheless, collectors now invariably consider all pens with the classic Equi-Poised profile as Equipoises -- and with reason, since it has been demonstrated that the "Gold Seal pens" were also being advertised as "Equi-Poised" as early as December 1930.
There is yet another Wahl-Eversharp design that is often categorized as an Equi-Poised, probably incorrectly. This is essentially a standard, cylindrical Signature pen to which tapered end pieces have been added. As far as is known, this rather makeshift design does not appear in any Wahl catalogs or advertisements, suggesting that it was never intended as a flagship model. As a transparent attempt to retrofit and update old pre-streamline stock, it most likely represents a parallel response to the challenge of Sheaffer's Balance, contemporary with or postdating the introduction of the original Equi-Poised. As such, the "transitional" label so often applied to this model is surely mistaken, for all evidence indicates that Wahl embraced streamlining quickly and decisively. Once Sheaffer made its move, Wahl followed with its own Balance knockoff that same year, and within two years had released both the classic Equi-Poised and the Doric. Putting the catalogs of 1929 and 1932 side by side dramatically illustrates what a turning point this was.