This replacement or spare magazine is compatible with your FN SCAR 17. It is constructed of DuPont Zytel polymer with injection molded mag follower and mag spring formed from chrome silicone wire. Made in the USA.
Specifications:

Caliber	308 Winchester/7.62 NATO
Capacity	20
Finish	Black
Model	FN Scar 17
Material	Polymer
Type	Detachable
Model Fit	SCAR H/17
Brand Fit	FN
Max Capacity	20