Two types of player actions were made. Both had the patented "trapezoid" tracker bar, which had the appearance of the hole divisions, as the serpentine paper filler in the common corrugated box. It may be that the same tracker bar was used in other types of player actions, as Simplex literature mentions this possibility, but there is no evidence of this showing up in any of the fifty actions in this listing.

Until 1914, Simplex made both a double valve and single valve action having a leathered rectangle of wood for a valve which was secured in a cubicle of the divided valve compartments. The cloth tail of this valve was secured by a wooden stick above and glued to the floor of this compartment. This three tier stack was designed to be "universal" in adapting to various piano scales, but instead of changing the set-up for the valve compartments, the metal fingers of the pneumatics were attached with various degrees of sideways extensions to advance or catch up with the scale. This was very awkward, and since, by this time, so many different scales were being accommodated in adding new customers, Simplex decided it was far more economical to make the screw-on pneumatic unit, and scale the spacing through the holes on the mounting board. Thus, the birth of a new player action that held close second to Standard in popular usage.

Simplex also made a Recordo player action. Information about that system is located here.