The HERA SFU folding shaft adapter was developed for the Hera TRIARII shaft system and gives the system a more compact size so that it can also be transported for example in a backpack to the shooting range. The Hera SFU can be used with standard M4 / AR15 without buffer recoil in the buffer tube or Triarrii-like systems. Cannot be used with buffer systems where the bolt carrier passes into a buffer tube. (i.e. not suitable for AR15, M4 or similar systems). Available in black. Can be used in many different weapon platforms using a standard M4 receiver thread size.