A few years back, they were sold for various guns, I think for $12 during the ban
The ones I played with were very poor, thin stainless or nickeled sheetmetal, crude folds, sharp edges and cheapo plastic followers and floorplates.
Mine were for a 459 S&W but they all looked the same in quality...not good.
Pass on the 30 rounders for the beretta too, inferior quality with too many problems, unless you just want to "play" with one to find out first hand.
You may even get them to work, short term...I don't think there is much repeat business on those mags, usually first time buyers looking at the price & capacity only.