FN 20100502 502 10rd 22 LR Black Steel
https://www.tandktactical.com/shop/845737013448-fn-20100502-502-10rd-22-lr-black-steel-29349
https://www.tandktactical.com/web/image/product.template/29349/image_1920?unique=48add7b
This magazine is compatible with your FN 502.
