SIG Air M17 21rnd Gas Magazine

I am selling this basically brand new 21-round gas magazine for the SIG ProForce M17 airsoft pistol.

I bought this about a month ago. It works perfectly with no leak and feeds smoothly. However, due to my testing and shoot practice, it has a very minor scratch at the top of the magazine on its side. I only realised later that I do not need or want another magazine.

Price is a little negotiable.