The models of the Specna Arms ONE series come with a metal body with individual serial number, which has been refined with a powder coated surface. Inside, a robust gearbox ensures reliability and flexibility, as it is equipped with the "Enter & Convert" or "SEAC" quick spring change system. This way the performance can be changed in just a few simple steps. In addition to the factory built-in spring, Specna Arms supplies an additional M90 spring, which can reduce the AEG's performance to approx. 310 FPS.