HK416D is developed by Heckler & Koch based on the AR15 platform and conceived as an improvement to the M4 Carbine with the notable inclusion of a gas-piston system derived from the G36 series. HK416 was called HKM4 when the project started, but this was changed to 416 in response to a trademark infringement suit filed by Colt. 416 is widely used by the police forces or army which used M4 / M16 before as 416 has the similar control as M4/M16 had. Also user can buy the upper receiver kit with handguard, barrel, gas system and sights as they want to bulid up the rifle with their original lower receiver, or they can buy as a fully assembled, stand alone rifle.

Besides, 416 also have new variant as follow,
M27 IAR: M27 Infantry Automatic Rifle, a heavy barrel type 416 developed from D16.5RS (16.5 barrel type) was equipped by US Marine
HK416C: Ultra-compact Variant
MR223 / MR556: Civilian Version 416 which only have semi-auto. 223 is for German Market and 556 is for US market
HK417: Larger Caliber variant chambered for 7.62x51mm NATO

Features:
‧Comes with a plastic upper and lower reciever with a metal 20mm rail
‧Comes with a plastic 20mm rail handguard
‧Comes with a metal 11.5" outer barrel with fixed muzzle
‧Comes with front folding sight and adjustable rear sight
‧Comes with a metal sling attachment at the rear
‧Comes with a plastic 3 position crane stock and metal stock tube
‧Comes with a plastic grip with anti-slip texture
‧Included a 300 rounds Hi-Cap mgazine

Specifications:
Length: 670mm / 780mm (stock extended)
Barrel Length: ~250mm
Weight: 2424g (with magazine)
Color: Black
Material: Plastic, Metal
Shooting Mode: Safety, Semi-Auto, Full-Auto
Magazine Capacity: 300 rounds
Bullet Type: 6mm BB
Battery: 7.4V-11.1V Lipo Stick or Lipo 3 Stick Type Battery
Power(Muzzle Velocity): 360-380 FPS (0.2g BB)
Manufacturer: Classic Army