"SG" is an abbreviation for Sturmgewehr or "assault rifle". The SG 550 is an assault rifle manufactured by Swiss Arms AG  in Switzerland. The rifle is based on the earlier 5.56mm SG 540.

Features:
- 134A / Green Gas powered
- Comes with Steel upper receiver with "SIG SAUER Inc. Exeter-nh SAN Made in Switzerland" marking
- Comes with Steel lower receiver
- Comes with Alloy Tactical Rail handguard
- Comes with Alloy outer barrel with flash hider
- Comes with Metal flip-up front and rear sight
- Comes with Polymer folding stock
- Comes with Polymer non-slip pistol grip
- Comes with Metal bolt and charging handle
- Comes with Steel trigger, ambi selector, ambi magazine release and bolt release
- Package includes Metal 32 rounds gas magazine

Specifications:
Length: 745mm / 480mm (Total Length)
Weight: 3268g (with magazine)
Color: Black
Material: Steel , Metal, Polymer
Hop-up: Adjustable
Shooting Mode: Safety , Semi-Auto , Full-Auto
Magazine Capacity: 32 Rounds
Bullet Type: 6mm BB
Gas: 12KG (Green Gas)
Power(Muzzle Velocity): 350 FPS (0.2g BB, Green Gas)
Manufacturer: GHK