The CM028S is an entry level AEG replica of the possibly most famous Russian assault rifle. It's whole receiver has been made out of high quality, durable plastic, with well-made imitations of wooden elements - the stock, grip and pistol grip. The replica's quality not only is not lower than the quality of other manufacturer's products, but presents a higher quality than most other similiar products available on the market. 
The replica's reenforced steel torques are what makes this replica really stand out among its likes and the mushroom-shaped piston head improves the pneumatic system's work. A non-orthodox hop-up chamber allows for the replica to obtain a high muzzle velocity even straight out of the box. 
In the S variation, the replica has been equipped with a lightweight stock which can be folded under the gun.