Power up +fps rings package

-4pcs/package (instead of 2pcs as before)

-CNC POM made

-fits APS2 spring guides, include SRS, Mod24, ssg24 and other 9mm spring guides

-each rings adds ~5fps depending on setup, both on light and heavy bb (increases joule creep)

-addable amount of rings depends on spring coil number and wire thickness (up to 15 rings in some cases)