This is a GG&G, Inc. Side Saddle, model GGG-2004.
The GG&G Remington TAC-14 Side Saddle Shell Holder (Five Shot) provides fast access to your rounds at an angle that matches your hand. The TAC-14 Side Saddle mounts solidly to receiver using provided steel trigger pin replacement bolts.
Features:
6061 T-6 aluminum
Non-marring backing plate
No modifications are required to the weapon for installation