All current generation barrel extensions which fit SRS-A1 rifles. These are Right-hand extensions, left hand barrel extensions are available upon request.
The SRS barrel extension is the interface between the monolithic receiver and the match-grade Lother Walther barrel. Because the barrel is indexed on the feed ramp of the barrel extension, it is a critical piece to the repeatable, high-level of accuracy achieved in the Desert Tech SRS platform. This is just for the extension itself.