Allows you to mount stocks on your HiCapa. Can either be Picatinny Rail or Buffer Tube. printed out of high quality and durable parts There will be two versions included with your purchase, one for HPA adapters (raised higher up), and another for regular mags (lowered by an inch) These are printed in a way where simply bumping it or dropping it won't shear through the layer lines. does not come with HiCapa, buffer tube nor stock. WILL come with a m5 nut and a Bolt, how ever.