This is the Lancer A5AWM 20 round steel feed lip magazine in .300 Black Out (.300 BLK) in Translucent Smoke.
Lancer Systems developed their L5 Advanced Warfighter Magazine (L5AWM) to have the weight benefits of a polymer magazine with the durability of steel, by having one piece wrap around steel feed lips combined with a durable polymer body with an easy to grip surface texture.
They are very durable and ideal for use in challenging weather conditions.
Compatible with all AR15 and STANAG formats including AR15/M4, HK416 and SA80.