Aero Precision has designed and have now released their AR15 Gen 2 Lower Receivers.
The Gen 2 lowers feature a nylon tipped upper tension screw that will allow the user to fine tune the fit of the two receivers. The tension set screw is inserted in the grip tang of the lower and will provide a tight fit with any standard AR15 upper.
Though Aero Precision usually has a very wide variety of color finish options, the Gen 2 lower will initially only come in anodized black.
Currently these features are only available in the AR15 standard lower receivers, though will be available in other configurations in the near future.
The Gen 2 lower retails for $90.00 and can be ordered through their webpage at: http://aeroprecisionusa.com/aspx/store/productdetail.aspx?pid=49