We've covered the two-piece magwell from Lancer previously, but this new design has some important changes. Obviously, the change to a single piece of 6061 T6 aluminum rather than two pieces is the most obvious, but the one-piece magwell now installs without tools (well, other than something to depress the trigger guard detente for installation).
Lancer System's one-piece magwell allows the same rapid reloading of your AR-15 as the two-piece, with a generously flared opening designed to assist in guiding magazines into the well. Reducing the adapter to a single piece reduces components, eliminates the need for an allen wrench and simplifies the process greatly. While the two-piece magwell was certainly not difficult to install, the one-piece is even simpler, and simpler means you're more likely to undertake the task.