This magazine is compatible with your FN SCAR 17S and SCAR 20S. It features a steel body with a low-friction follower.
Specifications:

Caliber	308 Winchester/7.62 NATO
Capacity	10
Finish	Flat Dark Earth
Model	SCAR 17S
Material	Steel
Type	Detachable
Model Fit	SCAR 17
Brand Fit	FN
Max Capacity	10