WGC Shop does a presentation of the custom M4 Gas Blowback rifle made by RA-Tech which they say is close to the design of the real steel. The NPAS technology is fully integrated here and the three round burst kit which should be sweet for those who like this feature. This package also includes rail covers in case nothing's mounted on the RAS.

If you're looking for this product, you can find it at WGC Shop.