A TriStar 12ga over/under shotgun is a boxlock action shotgun with two barrels stacked vertically, typically used for hunting and clay target shooting. Key features include a single selective trigger, a tang-mounted safety with barrel selector, and a fiber-optic front sight. TriStar over/unders are known for their affordability, durable construction with features like sealed actions and self-adjusting locking lugs, and a variety of models like the Setter S/T and Hunter Mag II.