This is a Magpul Industries Forend known as the MOE M-LOK, model MAG496-BLK.
The MOE M-LOK Forend is a drop-in replacement for the standard Remington 870 12ga shotgun" featuring an extended length and front/rear hand stops for improved weapon manipulation. Now updated with M-LOK slots for compatibility with all M-LOK accessories" this Forend adds modularity to the proven Remington 870 platform for sporting use" home defense" or on duty. NOTE: Not compatible with the Remington 870 Super Mag. Made in U.S.A.
Features:
Compatible with Remington 870 12ga shotguns
Reinforced polymer construction
M-LOK slots for direct attachment of accessories
Wrench included
