M&P Magazine Adapter for Milspec Lower

AR/M4 Beyond 5.56/.223
1

I know somebody makes a drop-in adapter that lets you use M&P 15-22 mags in a regular lower, but I can’t find my bookmark. As I recall BHO even works. Search didn’t work, but my search-foo isn’t too good.
Anybody have the link?

2

There may be others, but this is the adapter I remembered:

Boonie Packer Better-Mag S&W® .22 Rimfire Magazine Adapter (BMA II)

3

That’ it. Thanks Eagle.