All of the following are needed for an acrylic application service EXCEPT:

In an acrylic application service, the tools and materials required typically include a dappen dish, which is used to hold the liquid monomer and polymer powder, and nail primer, which prepares the natural nail for acrylic application and helps with adhesion. Polymer powder is essential as it forms the solid part of the acrylic system when combined with the liquid monomer.

While an accelerator can speed up the curing process of the acrylic, it is not always necessary for the application itself. Many nail technicians choose not to use an accelerator, relying instead on the natural curing time of the acrylic products. Thus, it is the element listed that is not universally required for every acrylic application, making it the exception among the mentioned items.