This is a pretty clever new take on the AR-15 safety selector. The Battle Arms Development, Inc. Ambi Safety Selector is an ambi selector that allows the user to choose between several different sizes and shapes of selector lever on both sides of the rifle.
There are good reasons to have an ambi selector even if you are a right handed. For instance, you may have to switch to your weak side in order to clear a corner or you may lose full or partial use of your strong hand. The nice thing about this lever is that you could put a short or slim lever on the side that you do not typically use so that it is out of your way or you could put a larger lever on your weak side to make it easier for your weak hand to manipulate.
If I were to install one of these, I would give the screws a good dose of Loc-Tite and I would suggest that you do as well. Screws always make me nervous and they certainly could be a downside to gear like this. Shooters should always weigh the pros and cons carefully if they ever choose to replace a simple part with a more complicated one.