The Vityaz —“knight” in Russian— was developed at the request of Russian special units as an evolution of the relatively unsuccessful PP-19 Bizon. Izhmash used the AK platform as its basis and developed a more conventional, compact submachine gun adapted to police and tactical work. 

Weight: 2850 g 
Length: 705 mm 
Main parts manufactured in steel. 
Small parts manufactured in aluminium and lightweight alloys. 
Other parts manufactured in reinforced polymer. 
Stock: Skeletonised and folding (para style) 
Picatinny rail (MIL-STD-1913) for accessories 
Magwell for faster reloads 
Wiring: 15 AWG 
Connector type: T-connector 
Rear sight: Adjustable 
Cover plate: With Picatinny rail (MIL-STD-1913) 
Mount for optical devices 
Fire selector: With tactical lever 
Spring release 

01. Gearbox 
Reinforced Version 3 gearbox compatible with Marui parts. 
02. Quick-change spring 
M100-type spring and metal spring guide with bearings. 
03. Piston 
Polymer piston body and head, with full metal teeth and bearing-equipped head. 
04. Cylinder 
CNC-machined, ported stainless steel cylinder. 
05. Nozzle 
CNC-machined POM (thermoplastic) nozzle with O-ring for improved sealing. 
06. Trigger 
Electronic straight “micro-switch” trigger (compatible with GATE and PERUN ETUs). 
07. Inner barrel 
PCP-grade 6.01 mm precision barrel, 250 mm long. 
08. Hop-up 
New rotary-style hop-up chamber design manufactured in polymer. 
09. Motor 
New high-performance 24K neodymium motor with MIM (Metal Injection Molding) steel pinion. 
10. Gears 
Steel gears mounted on bushings, except for the motor gear, which runs on 8 mm bearings. 
11. Tappet plate 
Polymer tappet plate. 
12. MOSFET

This new MOSFET helps achieve a higher ROF and faster trigger response without the risk of burning out the electrical system.

Externally, it retains much of the AK family DNA. The pistol grip follows the AK-100 series style: large and comfortable for bigger hands, although a little more non-slip texture would be welcome. 
The upper Picatinny RIS is inspired by the Vityaz-SN and allows optics to be mounted directly. It also retains the typical AK side mount, so there is no shortage of options for installing sighting systems. 

Another interesting detail is that the safety physically blocks the charging handle when placed in its upper position.

But what really changes its appearance compared with a traditional AK is the submachine-gun magazine and its polymer housing, which make the whole platform more compact and visually closer to an MP5 than to a conventional AK.

The folding skeletonised stock, inspired by the AKS-74, retains the classic Russian profile with a few changes to improve ergonomics. It is simple, functional and considerably reduces the size of the replica when moving through confined spaces. 

A Vityaz that is instantly recognisable, but with internals considerably more modern than its Soviet-looking exterior might suggest.