This Mossberg manufactured 18.5" Security barrel features a bead sight, cylinder bore, and matte blued finish. It is compatible with Remington 870 12 gauge models. Note: Not compatible with 870 12 Gauge 3.5" Magnum models.
Specifications:

Caliber or Gauge	12 Gauge
Length	18.5"
Model	Security
Twist
Sights	Front Bead
Bore Type	Cylinder Bore
Finish	Matte Blue
Type
Chokes Included
Choke Configuration	Rem Choke
Barrel Type	Security
Ammo Type
Barrel Features