The KRYTAC Piston is one of the work horse components in the mechbox. The main construction of the piston is polymer. All of the polymer piston teeth are reinforced on both sides and the first 4 teeth made of metal. The 2nd to last tooth of the piston is absent to ease in the fine tuning of the AEG, for the tech savvy crowd. The KRTYAC Piston Head is made of polymer and is ported allow the cylinder to quickly refill itself with air in preparation for the next shot. The polymer construction is ideal to keep the overall weight of the piston low which reduces wear and tear and allows for easy movement. This is the standard piston assembly on KRYTAC AEGs but can serve as a good replacement, or even upgrade, to other AEG piston assemblies.