AEG cylinders are a key part of the pressure system inside the gearbox of an electric airsoft gun. The cylinder acts as the chamber where the piston compresses air before firing, generating the pressure that propels the BB through the barrel.

Choosing the correct cylinder affects power, gearbox efficiency, and shot consistency. Cylinders are available in different materials, coatings, and port configurations, and naming conventions may vary between manufacturers.

Ported vs non-ported cylinders

The port position determines how early air compression begins during the piston movement, which is directly related to the length of the inner barrel.

Non-ported cylinder (Type 0)
Recommended for long inner barrels, typically over 450 mm. Maximizes available air volume.

3/4 port cylinder (Type A)
Commonly used with inner barrels around 360–460 mm, such as many M4 setups.

2/3 port cylinder (Type B)
Suitable for barrels roughly 300–400 mm long.

1/2 port cylinder (Type C)
Designed for shorter barrels, typically under 300 mm.

Because naming can vary between manufacturers, always verify the specifications in the product description.

Materials and coatings

AEG cylinders are typically made from aluminum, brass, or steel. Some models feature coatings such as Teflon or Nitroflon, which reduce friction and can improve piston movement and overall gearbox consistency.

Compatibility

The cylinder works together with the piston, piston head, and cylinder head. For best performance, all parts should match in dimensions and air seal. Always ensure the cylinder is compatible with your gearbox version (e.g., Version 2, Version 3).