Scale: 1/350 (true scale)

Set includes 4 turrets with barrels.

A set of 5"/54 cal. Mk.41 twin-gun mounts (turrets) is available separately.
 
This set of three-gun turrets (properly called a "gunhouse") was specifically designed for the Iowa class battleships of the U.S. Navy, and later intended for the even larger Montana class battleships.  Each turret was to mount three 16-inch/50 caliber Mark 7 naval rifles.  This was the largest naval turret and gun used operationally by any US Navy warship.  The Iowa class carried three of these huge turrets (available separately).  The Montana class would have carried four.

Features of this multi-part, scale model kit:
dimensions scaled from scans of original builder's blueprints and confirmed by measurements taken from actual gunhouses on the real ships
armored rangefinder hexhead bolt and domed screw details
rooftop screwhead detail, properly numbered, sized and positioned
asymmetrically positioned underside ventilation trunks (Iowa class as-built 1943-1945 configuration)
asymmetrically positioned underside crew access hatches
 
These turrets are precisely scaled to match the dimensions of the real turrets as recorded in official Navy blueprints.  They are not 3D-printed copies of any resin or plastic model ship parts and therefore are likely to be differently shaped and sized than the turrets found in your plastic or resin kit.  Some adjustment to your kit's parts or any aftermarket items such as photoetch railings may be necessary for best fit.

© Model Monkey LLC.  This 3D-printed product may not be copied or recast.

This turret set is suitable for Montana class battleships:
BB-67 USS Montana
BB-68 USS Ohio
BB-69 USS Maine
BB-70 USS New Hampshire
BB-71 USS Louisiana 
 
Regarding the Mark 7 gun, from Wikipedia: "These guns were 50 calibers long—or 50 times their 16-inch (406 mm) bore diameter which makes the barrels 66.6 feet (20 m) long, from breechface to muzzle. Each gun weighed about 239,000 pounds (108,000 kg) without the breech, or 267,900 pounds (121,517 kg) with the breech. They fired projectiles weighing from 1,900 to 2,700 pounds (850 to 1,200 kg) at a maximum speed of 2,690 feet per second (820 m/s) with a range of up to 24 miles (39 km). At maximum range the projectile spent almost 1½ minutes in flight. Each turret required a crew of 79 men to operate. The turrets themselves cost US$1.4 million each, to which the cost of the guns had to be added."