3" and will fire 2 3/4 as well. Remington Barrel Remington 870 Wingmaster 12 Gauge 3" 28" Rem Choke with Improved Cylinder, Modified and Full Chokes Vent Rib Standard Contour (Bradley Front Sight and Middle Bead) Blue

Manufacturer says it will safely handle both 2 3/4" and 3".

For more than 200 years, Remington firearms have been forged from the untamed spirit that will always define our nation. The proud tradition that began with Eliphalet Remingtons first hand-built rifle in 1816, continues to this day. Remington innovation is always ahead of its time, as evidenced by their rich history and long line of legendary firearms.
If you own a Remington shotgun you know quality and, that when it comes to replacement parts, there's only one brand good enough Remington. Remington offers a wide variety of original factory barrels ranging in styles from vent rib, to cantilever to rifle sighted, so you never have to compromise the superb craftsmanship and dependability that make Remington ownership a matter of pride. Whether you want your Remington shotgun to perform like two, or you're looking to restore an old friend, there's no substitute for Remington replacement barrels.
Features and Specifications:
Manufacturer Number: 224580
Remington 870 12 Gauge 28" Wingmaster Vent Rib Barrel Black
Wingmaster standard contour barrel
Length : 28"
Chamber: 3 Inch
Model : 870 Wingmaster
Chokes : Rem Choke - Full, Modified, Improved Cylinder
Sights : Vent Rib
Bore : Smooth
Bradley front sight and middle bead
Color: Blued
Fits:
Remington 870 12 gauge shotguns