CMMG 55AFF2F Upper Parts Kits Pins & Springs AR15
https://www.tandktactical.com/shop/815835011981-cmmg-55aff2f-upper-parts-kits-pins-springs-ar15-14215
https://www.tandktactical.com/web/image/product.template/14215/image_1920?unique=5a78b6e
Parts Kit, AR15, Upper Pins and Springs