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This is a replacement charging handle for the GHK G5 GBBR. This model is a Small HK style with a solid center.
For a larger version, check out the H&K Solid Large version, which is the same design but slightly oversized and works well with gloves or large hands.
It should swap straight across with minimal if any fitment or sanding, though occasionally a print will have slightly tighter dimensions and will need a little finishing work. Most common are the pin holes, which are difficult for the machines to make nice round shapes that small.