"B-21U handguard" milled rail is designed for Vityaz-SN and rifles based on it (Saiga-9, TR9 Paradox).

"B-21U handguard" rail forms a Picatinny rail at the bottom and two Basis rails on sides. 

Basis rail allows to install additional accessories directly on handguard, in particular:

• B-2, B-2L, B-2M, B-2U Picatinny rails; 
• A-1L, A-2L slingmounts; 
• RL-1 hand stoppers; 
• NPN-2 Basis rail covers; 
• FP-3 wire holders; 
• B-19 or B-19N upper handguards; 
• B-22 rear sight rail. 

Picatinny rail on the bottom allows you to install:

• RK-0, RK-1, RK-2, RK-4, RK-5, RK-6 grips;
• tactical flashlights;
• laser pointers;
• bipods;

Benefits during operation:
- improves the cooling of the barrel of the weapon in the area from the receiver to the gas tube;
- makes it possible to attach additional equipment.

Specifications:

Material: D16T aluminum alloy;
Weight: 130 ± 10g;
Overall dimensions: (165x38x40) ± 5mm;
Operating temperature range: from -50 to +50°С.

In the kit:

B-21U handguard	1 pc.
Manual	1 pc.

To install "B-21U handguard" rail on a weapon, you need to:
1. Make an incomplete disassembly of the weapon and remove the regular handguard.
2. Install the "B-21U handguard" instead of the regular handguard. B-21U should be installed very rigidly, for that it is necessary to:
- install the regular handguard retailer on B-21U;
- attach B-21U to the receiver;
- place a wooden or metal spacer on handguard retainer, hammer in B-21U rail into the receiver of the weapon;
- close the lever on handguard retainer.
3. Assemble the rifle.
Attention! Do not file the handguard during installation. This can lead to the formation of a backlash at the junction of the handguard with the receiver.
The hardness of the handguard landing determines the hardness of the landing of the sights, which affects the accuracy of the shot.

The warranty period for the product is 60 months.