There are 2 main differences; the size and the weight limit. You may also check out our display guide for an overview of which display series suit your needs. In general, our sixth series are smaller and designed for 1:6 scale figurines while the DF can handle larger, heavier statues (typically 1:4) and the MAX series are designed to hold the largest and heaviest collectibles (Dioramas or 1:3 and above). Using weight limits as a guide: SIXTH series can support up to 15kg weight limit. DF series can support up to 15kg weight limit. DF series with enhancement upgrade can support up to 30kg weight limit. MAX series models (MAX70 / MAX70 Plus / MAX150 / MAX150 Plus) can support up to 40kg weight limit. MAX series models (MAX140 / MAX140 Plus) can support up to 70kg weight limit.