Slim and sleek, this gas block is a gorgeous sporty little number; smooth and stealthy like a B2. In some M16 pattern weapons the gas block is functional for some kinds of front kits and in another cases its just aesthetic. In either case, if your putting a custom piece together, this is a must see.
If your building a modgun from the ground up, why use a stock gas block when you could use something like this?
Alternatively, maybe you don't want to bastardize your weapon too much but are looking for something small and subtle just to give its visual flavor a bit of that personalized edge with a touch of that Daniel Defense look, particularly when coupled with a Daniel Defense rail system.