Excellent gas block - 2A Armament Titanum Gas Block

If you are building a light weight AR15 this is a great gas block. Weighs very little, but built very strong. It's nice that Titanium expands less than steel when heated. This means the seal gets tighter as the barrel heats up. It is a bit difficult to get the gas tube pin installed due to the curved shape of the block. Prepare to be frustrated, but a Gieselle gas pin install tool helps out a lot.