Provided that it’s a brace, as opposed to an real butt stock, Then you really are good to go sans-tax stamp. "It can be very reliable for the price. Stock doesn't wobble when unfolded and no creaks everywhere. Suits my WE G17 Gen five with little wobble, not that noticable. https://glock-18c-parts-kit96396.full-design.com/the-single-best-strategy-to-use-for-glock-18-parts-kit-69378197