King Arms has introduced into its offer a product that is called a "magwell" and is intended for replicas of Magpul's PMAG magazines. However, no information has been provided about compatibility with magazines available on the market. We only know that the handles will be available individually (KA-MAG-84-BK) and in sets of three pieces (KA-MAG-84-BK-III).
Edit: we know what magwells and magpulls are. In the source information from King Arms, however, there is mention of magwells - hence we wrote this word in quotes.