The new Br4 lower is a more traditional rifle version of our Mk4 platform that is designed to use Remington 870 compatible stocks, and DISSENT Mk4 upper groups.Whether you want a pistol caliber carbine for home defense, a modular hunting rifle, or an easy suppressed shooting host, an entire range of calibers including 5.56mm, 300 BLK, 9mm, 22 ARC, 6mm ARC, 6.5 Grendel, and 350 Legend means there's a caliber option for however you intend to use the DISSENT Br4 and is always ready to expand to a new role.Included are the cross-bolt safety and MagpulSGA870 pattern stock.NOTE: Br4 lowers are only designed for use with DISSENT Mk4 Upper Groups.