This is a Ergo Grip Rubber known as the Sure Grip, model 4011-BK.
The ERGO Suregrip AR15/M16 Grip Kit is a simple" ergonomic upgrade for your AR-15. The textured rubber grip ensures a soft" positive grip surface under all conditions" reducing fatigue" and improving comfort. The original ergonomically designed ERGO Grip fits all AR-15/M16 rifles.
Features:
Fits AR-15 type firearms in .223 and .308
Ergonomically correct finger grooves
Virtually impervious to oils and solvents
Comes with The Gapper
